fix(pi): emit parameters and execute in the generated pi adapter

[musichen]

Problem

The generated Pi extension (~/.pi/agent/extensions/cbmem.ts) registers each MCP tool as:

pi.registerTool({ name: 'index_repository', run: (args, ctx) => call('index_repository', args, ctx?.signal) });

Pi's ToolDefinition requires label, description, parameters, and execute. The run-only shape is accepted by Pi's loader but produces tools that fail in two ways:

1. No parameters schema - strict providers such as xAI/Grok reject the request with 422 missing field parameters (OpenAI and other providers tolerate the omission, so it only surfaces on some providers).
2. No execute - the tool is uncallable, because Pi invokes execute, never run.

Once execute was wired up, a third problem surfaced: execute forwarded the raw MCP JSON (which has no content array) instead of Pi's required result shape, crashing the TUI's getTextOutput on result.content.filter(...).

Fix

The adapter now emits the full tool shape from the registry:

pi.registerTool({
  name: 'index_repository',
  label: 'Index repository',
  description: '...',
  parameters: { ...input_schema... },
  execute: async (args, ctx) => {
    const result = await call('index_repository', args, ctx?.signal);
    if (result && typeof result === 'object' && result.error) {
      throw new Error(String(result.error));
    }
    const content = result && Array.isArray(result.content)
      ? result.content
      : [{ type: 'text', text: JSON.stringify(result ?? null, null, 2) }];
    return { content, details: result ?? {} };
  },
});

Specifically:

• Added cbm_mcp_tool_title and cbm_mcp_tool_description accessors so the adapter reads metadata from the same registry that backs tools/list, instead of drifting.
• The input_schema is embedded directly as a JSON object literal (compact JSON is valid JavaScript), avoiding a JSON.parse indirection.
• Added a JS-string escaping helper so long descriptions with apostrophes/backslashes/newlines serialize safely.
• call now passes --json so the CLI emits the raw MCP result instead of human-readable text that JSON.parse cannot parse.
• execute returns Pi's required { content, details } shape: it passes the MCP content array through, throws on transport errors, and stringifies anything else.

Tests

• Added client_adapter_pi_emits_parameters_and_execute asserting execute/parameters are present, the legacy run: shape is gone, the schema is embedded, and --json is requested.
• Built the CLI and verified the generated cbmem.ts loads and returns a valid result shape for success, error, null, and plain-object results.
• agent_clients suite: 32/32 passing.

[github-actions]

Thanks for opening this — it has been seen, and it is queued.

This note is automated, but it is not a brush-off: it exists so you know where your PR stands instead of having to guess from silence.

Current review status: working through a backlog. 0.9.1-rc.1 is out, so the release freeze that held reviews is over — but it left a large queue of open pull requests behind it, and we are reading through them oldest-first. The background is in discussion #1144.

What that means for this PR, concretely:

• It will not be closed for inactivity. No stale bot touches pull requests here.
• It may still sit a while before a human reads it. That is on us, not on you.
• Older PRs are read first, so a recent one is not being skipped — it is behind a queue.

Things that will genuinely speed it up whenever review does happen:

• Keep it rebased on main — the tree is moving quickly right now, and a conflicting branch cannot be reviewed as the diff you intended.
• Get CI green, or say which failures you believe are pre-existing.
• Keep the change to one claim. Bundled features and refactors get split before they get merged, which costs you a round trip.
• Every commit needs a sign-off (git commit -s) — CI enforces DCO.

If this fixes a bug, a reproduction we can run is worth more than a description of the symptom.

Thanks for contributing, and sorry in advance for the wait.