diff --git a/packages/extension/AGENTS.md b/packages/extension/AGENTS.md
index aa8eff9..1d55203 100644
--- a/packages/extension/AGENTS.md
+++ b/packages/extension/AGENTS.md
@@ -38,14 +38,14 @@ Sound like it — not a generic assistant.
 ## Workflow (this is the whole job)
 
 The script is authored at an explicit TRUST TIER and launched through the gate
-`amico-run --spec`. All paths below use the active Problem workspace
+`{{AMICO_RUN}} --spec`. All paths below use the active Problem workspace
 `~/.amico/problems/<slug>/` (open/create/rename with `amicode_problem`; the
 workspace owns `solve.jl` — never author in `/tmp`).
 
 1. **Resolve the tier** once the System + Formulation are recorded. From the
    Formulation, run:
    ```bash
-   amico-run resolve --platform <transmon|rydberg|…> --kind <gate_synthesis|state_prep|…> --size <n>
+   {{AMICO_RUN}} resolve --platform <transmon|rydberg|…> --kind <gate_synthesis|state_prep|…> --size <n>
    ```
    It prints JSON: `{tier, source?, template_path?|exemplar_path?, packages, blocked_higher?}`.
 2. **Author `solve.jl` per the tier** into `~/.amico/problems/<slug>/solve.jl`:
@@ -66,7 +66,7 @@ workspace owns `solve.jl` — never author in `/tmp`).
 4. **free tier only — generate the env** (vetted/composed use the provisioned
    env unless `resolve` said otherwise):
    ```bash
-   amico-run sandbox ~/.amico/problems/<slug> --packages <comma-list from resolve>
+   {{AMICO_RUN}} sandbox ~/.amico/problems/<slug> --packages <comma-list from resolve>
    # then run the printed  JULIA_PKG_USE_CLI_GIT=true julia --project=… Pkg.instantiate()  line
    ```
 5. **Estimate, confirm routing, then assemble `~/.amico/problems/<slug>/solvespec.json`.**
@@ -79,7 +79,7 @@ workspace owns `solve.jl` — never author in `/tmp`).
      it specifies and do **not** ask where the solve should run. When the section is
      **absent**, this solve is LOCAL: run local and do NOT offer remote.
    - **Estimate (informs, never decides).** Run
-     `amico-run estimate ~/.amico/problems/<slug>/solve.jl` — it prints ONE JSON line
+     `{{AMICO_RUN}} estimate ~/.amico/problems/<slug>/solve.jl` — it prints ONE JSON line
      `{sizeClass, estimatedBytes, localRamBytes, offloadSuggested, reason, …}`. Surface it
      at the decision point: tell the researcher the `sizeClass`, the `estimatedBytes` vs
      local RAM, and the `reason`. The estimate only **suggests**, and only where a choice
@@ -96,7 +96,7 @@ workspace owns `solve.jl` — never author in `/tmp`).
    env: `{{JULIA_PROJECT}}` (the provisioned env) for vetted/composed, or the
    sandbox env from step 4 for free (it must equal the spec's `env.project`).
    ```bash
-   ( nohup amico-run --spec ~/.amico/problems/<slug>/solvespec.json \
+   ( nohup {{AMICO_RUN}} --spec ~/.amico/problems/<slug>/solvespec.json \
        --project {{JULIA_PROJECT}} --lab default \
        ~/.amico/problems/<slug>/solve.jl \
        > ~/.amico/problems/<slug>/solve.log 2>&1 < /dev/null & )
@@ -116,9 +116,9 @@ workspace owns `solve.jl` — never author in `/tmp`).
    agree/disagree honestly — a `free` run is UNTRUSTED and cannot be promoted
    until verification agrees.
 
-There is **no MCP server**. The solve runs through `amico-run` via bash; the
+There is **no MCP server**. The solve runs through `{{AMICO_RUN}}` via bash; the
 `amicode_*` tools below (when present) record design state under the Problem
-workspace — they never replace the bash launch. `amico-run --help` prints usage.
+workspace — they never replace the bash launch. `{{AMICO_RUN}} --help` prints usage.
 
 ### Bookkeeping verbs (`amico` — same bash surface)
 
@@ -322,7 +322,7 @@ Stages, in order:
    below); pass them to `amicode_solve` (it records them on the Formulation and
    writes the Run entity, stamped with the resolved `tier`), then author
    `solve.jl` and launch it through the tiered gate — **follow the Workflow
-   steps 1–7 above** (`amico-run resolve` → author per tier → `amico-run --spec`
+   steps 1–7 above** (`{{AMICO_RUN}} resolve` → author per tier → `{{AMICO_RUN}} --spec`
    via bash). For a stock single-qubit transmon gate this resolves to the
    **vetted** tier and is exactly the fill-in-the-block flow.
 7. **INSPECT** — the Run Inspector opens itself and streams the live pulse;
@@ -411,7 +411,7 @@ lists it — honestly caveated (see the PLATFORM stage).
 
 ## The run-dir contract your script MUST emit
 
-`amico-run` writes `run.toml` (first) and `FINISHED` (last) itself. Your
+`{{AMICO_RUN}}` writes `run.toml` (first) and `FINISHED` (last) itself. Your
 script, running with cwd = the run dir, must emit:
 
 - `AMICODE_ITER iter=<n> f=<obj> inf_pr=<…> inf_du=<…>` to stdout, flushed,
@@ -493,6 +493,18 @@ correct loader in this Piccolo.
 
 **{{JULIA_PROJECT}}**. Always pass it.
 
+## Tool use
+
+- **The tools you need are at absolute paths already. Never hunt for them.** Use
+  `{{AMICO_RUN}}` and `{{JULIA_PROJECT}}` verbatim. Do **not** run
+  `which amico-run`, and never fall back to `find ~ -name …`, `find /usr -name …`,
+  or `pip list` to locate it — searching the filesystem for a path you were handed
+  is always wrong here. If a command genuinely fails, report the error and stop;
+  do not go looking for the binary.
+
+- Batch independent tool calls into one turn where it's natural; each turn is a
+  full round-trip. Serialize only when a later call needs an earlier result.
+
 ## Style & formatting
 
 The user is a quantum-control researcher — skip the basics, keep the physics
diff --git a/packages/extension/src/extension.ts b/packages/extension/src/extension.ts
index fbc3920..36d9238 100644
--- a/packages/extension/src/extension.ts
+++ b/packages/extension/src/extension.ts
@@ -423,7 +423,11 @@ export async function activate(ctx: vscode.ExtensionContext): Promise<void> {
     const parsed = parseLibraryRootSpecs(raw);
     return parsed.length ? parsed : undefined;
   };
+  // Absolute launcher path for AGENTS.md's {{AMICO_RUN}} — so the agent never
+  // needs `which`, and never falls back to scanning $HOME (417s measured waste).
+  const amicoRunPath = amicoRunBinDir ? path.join(amicoRunBinDir, "amico-run") : undefined;
   const opencodeProject = prepareOpencodeProject({
+      amicoRunPath,
     agentsSrc: path.resolve(ctx.extensionPath, "AGENTS.md"),
     // MODE-SELECTED vetted template: HP sessions get the Piccolissimo variant
     // (same run-dir contract, spline solver layer). An AGENTS.md instruction
@@ -573,6 +577,7 @@ export async function activate(ctx: vscode.ExtensionContext): Promise<void> {
         opencodeChannel.appendLine(`[solver] switching → ${mode}`);
         applyEntitlementForMode(mode, path.join(os.homedir(), ".amico", "amicode"));
         const project2 = prepareOpencodeProject({
+          amicoRunPath,
           agentsSrc: path.resolve(ctx.extensionPath, "AGENTS.md"),
           // Same mode-selection as boot; `mode` is the requested target of THIS
           // switch (the state file still reads status:"switching" here).
@@ -707,6 +712,7 @@ export async function activate(ctx: vscode.ExtensionContext): Promise<void> {
     }
     const port = vscode.workspace.getConfiguration("amicode").get<number>("opencodePort", 0);
     const project2 = prepareOpencodeProject({
+      amicoRunPath,
       agentsSrc: path.resolve(ctx.extensionPath, "AGENTS.md"),
       templateSrc: path.resolve(
         ctx.extensionPath,
diff --git a/packages/extension/src/opencode_config.ts b/packages/extension/src/opencode_config.ts
index b543d3f..6d3d561 100644
--- a/packages/extension/src/opencode_config.ts
+++ b/packages/extension/src/opencode_config.ts
@@ -464,6 +464,14 @@ export interface OpencodeConfigOptions {
   /** Julia project (--project) the agent should use; already resolved (see
    *  resolveJuliaProject). Substituted into AGENTS.md as {{JULIA_PROJECT}}. */
   juliaProject: string | undefined;
+  /** Absolute path to the `amico-run` launcher, substituted into AGENTS.md as
+   *  {{AMICO_RUN}}. PATH augmentation already happens at spawn time, but when it
+   *  fails the agent fell back to `which amico-run || find ~ -name amico-run`,
+   *  and an unbounded scan of $HOME costs ~2 minutes EACH: 128 such calls totalling
+   *  417s were measured in one session's history (2026-08-03). Handing over the
+   *  absolute path removes the reason to search at all. Undefined leaves the
+   *  placeholder resolving to the bare command (previous behaviour). */
+  amicoRunPath?: string;
   /** Scores repertoire root (SCORE.md manifests). Default: the bundled scores/. */
   scoresRoot?: string;
   /** Dir holding the user's entitlements.toml (access-code stub). Default: ~/.amico/amicode. */
@@ -524,7 +532,11 @@ export function prepareOpencodeProject(opts: OpencodeConfigOptions): OpencodePro
     : "# Amicode\nRead the template at {{TEMPLATE_PATH}}, fill params, run `amico-run <script>`.\n";
   const filled = raw
     .replaceAll("{{JULIA_PROJECT}}", opts.juliaProject ?? resolveJuliaProject(""))
-    .replaceAll("{{TEMPLATE_PATH}}", opts.templateSrc);
+    .replaceAll("{{TEMPLATE_PATH}}", opts.templateSrc)
+    // Absolute when we know it, bare command otherwise — a bare `amico-run` is
+    // exactly the pre-existing behaviour, so an unresolved bin dir degrades
+    // rather than breaking.
+    .replaceAll("{{AMICO_RUN}}", opts.amicoRunPath ?? "amico-run");
 
   // Score runtime ("data-defined, prompt-executed", scores spec §6): compile the
   // selected score (v1: boot-time selection of score #0, pulse-designer) over the
diff --git a/packages/extension/test/agents_md.test.ts b/packages/extension/test/agents_md.test.ts
index 4a9a9cc..c901481 100644
--- a/packages/extension/test/agents_md.test.ts
+++ b/packages/extension/test/agents_md.test.ts
@@ -6,8 +6,8 @@ const AGENTS = readFileSync(join(__dirname, "..", "AGENTS.md"), "utf8");
 
 describe("AGENTS.md teaches the D9/D10 script-authoring workflow", () => {
   it("teaches the tiered resolve → author → --spec launch (spec C), not a single bundled template", () => {
-    expect(AGENTS).toMatch(/amico-run resolve/); // tier resolution step
-    expect(AGENTS).toMatch(/amico-run --spec/); // the gated invocation it teaches
+    expect(AGENTS).toMatch(/\{\{AMICO_RUN\}\} resolve/); // tier resolution step (placeholder, substituted at prep)
+    expect(AGENTS).toMatch(/\{\{AMICO_RUN\}\} --spec/); // the gated invocation it teaches
     expect(AGENTS).toMatch(/solve\.jl/);
     expect(AGENTS).toMatch(/vetted/); // the three tiers named
     expect(AGENTS).toMatch(/composed/);
@@ -73,7 +73,7 @@ describe("AGENTS.md teaches the D9/D10 script-authoring workflow", () => {
 
 describe("AGENTS.md teaches the Δ10 (#63) routing UX", () => {
   it("runs amico-run estimate at solve-assembly and surfaces the estimate at the decision point", () => {
-    expect(AGENTS).toMatch(/amico-run estimate/);
+    expect(AGENTS).toMatch(/\{\{AMICO_RUN\}\} estimate/);
     expect(AGENTS).toMatch(/sizeClass/);
     expect(AGENTS).toMatch(/offloadSuggested/);
     expect(AGENTS).toMatch(/local RAM/i);
@@ -180,10 +180,9 @@ describe("AGENTS.md pulse-designer interview (Layer 0)", () => {
     expect(AGENTS).toMatch(/Never silently\s+co-optimize/i);
   });
   it("leaves no unknown {{...}} placeholder after session-prep substitution", () => {
-    const substituted = AGENTS.replace(/\{\{TEMPLATE_PATH\}\}/g, "/abs/solve_template.jl").replace(
-      /\{\{JULIA_PROJECT\}\}/g,
-      "/abs/julia",
-    );
+    const substituted = AGENTS.replace(/\{\{TEMPLATE_PATH\}\}/g, "/abs/solve_template.jl")
+      .replace(/\{\{JULIA_PROJECT\}\}/g, "/abs/julia")
+      .replace(/\{\{AMICO_RUN\}\}/g, "/abs/bin/amico-run");
     expect(substituted).not.toMatch(/\{\{[A-Z_]+\}\}/);
   });
 });
@@ -255,3 +254,45 @@ describe("HP solver-mode guidance: both imports", () => {
     }
   });
 });
+
+// Perf regression guard (2026-08-03). Profiling found 128 unbounded `find` calls
+// over $HOME — 417 seconds — because AGENTS.md said bare `amico-run` and the agent
+// fell back to `which amico-run || find ~ -name amico-run` when PATH missed. The
+// binary's absolute path is known at activation, so hand it over and remove the
+// reason to search.
+describe("AGENTS.md hands over the absolute amico-run path", () => {
+  const prepared = async (amicoRunPath?: string): Promise<string> => {
+    const { prepareOpencodeProject } = await import("../src/opencode_config");
+    const { mkdtempSync, readFileSync } = await import("node:fs");
+    const { tmpdir } = await import("node:os");
+    const { join } = await import("node:path");
+    const p = prepareOpencodeProject({
+      agentsSrc: join(__dirname, "..", "AGENTS.md"),
+      templateSrc: "/tmp/tmpl.jl",
+      juliaProject: "/tmp/proj",
+      vaultDir: "",
+      projectDir: mkdtempSync(join(tmpdir(), "agents-perf-")),
+      ...(amicoRunPath ? { amicoRunPath } : {}),
+    });
+    return readFileSync(p.agentsPath, "utf8");
+  };
+
+  it("substitutes the absolute path and leaves no placeholder behind", async () => {
+    const out = await prepared("/abs/bin/amico-run");
+    expect(out).toContain("/abs/bin/amico-run --spec");
+    expect(out).not.toContain("{{AMICO_RUN}}");
+  });
+
+  it("degrades to the bare command when the bin dir is unknown", async () => {
+    const out = await prepared(undefined);
+    expect(out).toContain("amico-run --spec"); // previous behaviour, not a broken placeholder
+    expect(out).not.toContain("{{AMICO_RUN}}");
+  });
+
+  it("forbids the $HOME scan and tells the agent to batch", async () => {
+    const out = await prepared("/abs/bin/amico-run");
+    expect(out).toMatch(/never fall back to `?find ~/);
+    expect(out).toMatch(/Batch independent tool calls into one turn/);
+    expect(out).toMatch(/Do \*\*not\*\* run\s+`?which amico-run/);
+  });
+});