Reduce prompt token overhead with leaner context injections

src/agents/pi-embedded-helpers.ts

@@ -16,6 +16,25 @@ import type { WorkspaceBootstrapFile } from "./workspace.js";
 
 export type EmbeddedContextFile = { path: string; content: string };
 
+const MAX_BOOTSTRAP_CHARS = 4000;
+const BOOTSTRAP_HEAD_CHARS = 2800;
+const BOOTSTRAP_TAIL_CHARS = 800;
+
+function trimBootstrapContent(content: string, fileName: string): string {
+  const trimmed = content.trimEnd();
+  if (trimmed.length <= MAX_BOOTSTRAP_CHARS) return trimmed;
+
+  const head = trimmed.slice(0, BOOTSTRAP_HEAD_CHARS);
+  const tail = trimmed.slice(-BOOTSTRAP_TAIL_CHARS);
+  return [
+    head,
+    "",
+    `[...truncated, read ${fileName} for full content...]`,
+    "",
+    tail,
+  ].join("\n");
+}
+
 export async function ensureSessionHeader(params: {
   sessionFile: string;
   sessionId: string;
@@ -88,12 +107,18 @@ export async function sanitizeSessionMessagesImages(
 export function buildBootstrapContextFiles(
   files: WorkspaceBootstrapFile[],
 ): EmbeddedContextFile[] {
-  return files.map((file) => ({
-    path: file.name,
-    content: file.missing
-      ? `[MISSING] Expected at: ${file.path}`
-      : (file.content ?? ""),
-  }));
+  const result: EmbeddedContextFile[] = [];
+  for (const file of files) {
+    if (file.missing) continue;
+    const content = file.content ?? "";
+    const trimmed = content.trimEnd();
+    if (!trimmed) continue;
+    result.push({
+      path: file.name,
+      content: trimBootstrapContent(trimmed, file.name),
+    });
+  }
+  return result;
 }
 
 export function formatAssistantErrorText(

src/agents/system-prompt.test.ts

@@ -34,7 +34,7 @@ describe("buildAgentSystemPromptAppend", () => {
     expect(prompt).toContain("<final>...</final>");
   });
 
-  it("lists available and unavailable tools when provided", () => {
+  it("lists available tools when provided", () => {
     const prompt = buildAgentSystemPromptAppend({
       workspaceDir: "/tmp/clawd",
       toolNames: ["bash", "sessions_list", "sessions_history", "sessions_send"],
@@ -44,7 +44,6 @@ describe("buildAgentSystemPromptAppend", () => {
     expect(prompt).toContain("sessions_list");
     expect(prompt).toContain("sessions_history");
     expect(prompt).toContain("sessions_send");
-    expect(prompt).toContain("Unavailable tools (do not call):");
   });
 
   it("includes user time when provided", () => {

src/agents/system-prompt.ts

@@ -85,7 +85,6 @@ export function buildAgentSystemPromptAppend(params: {
     new Set(normalizedTools.filter((tool) => !toolOrder.includes(tool))),
   );
   const enabledTools = toolOrder.filter((tool) => availableTools.has(tool));
-  const disabledTools = toolOrder.filter((tool) => !availableTools.has(tool));
   const toolLines = enabledTools.map((tool) => {
     const summary = toolSummaries[tool];
     return summary ? `- ${tool}: ${summary}` : `- ${tool}`;
@@ -160,9 +159,6 @@ export function buildAgentSystemPromptAppend(params: {
           "- sessions_history: fetch session history",
           "- sessions_send: send to another session",
         ].join("\n"),
-    disabledTools.length > 0
-      ? `Unavailable tools (do not call): ${disabledTools.join(", ")}`
-      : "",
     "TOOLS.md does not control tool availability; it is user guidance for how to use external tools.",
     "",
     params.modelAliasLines && params.modelAliasLines.length > 0