answer

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it does disclose a critical behavioral trait: 'A delegate waiting on one is blocked until you answer it,' i.e. this call has a real unblocking side effect. It also explains the origin of requests (MCP adapter tool-approval and elicitation prompts), which helps an agent recognize legitimate questions. It omits permission/auth requirements for the caller and what a successful answer returns.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the core purpose and immediately followed by the operational detail (where to get requestId). No filler or restatement of the tool name. Slightly dense mid-sentence clause, but nothing wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 3-required-param, no-output-schema tool with no annotations, the description covers purpose, prerequisite lookup, source of requests, and the blocking consequence. The main remaining gap is that `sessionId` is never explained and there is no statement of what a valid answer looks like beyond the schema's `value` types.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 33% (only `value` is described), so the description must compensate. It does add genuine meaning for `requestId` by pointing to `status` as its source. However, `sessionId` is left entirely unexplained in both schema and description, so the compensation is partial.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource ('Answer a question raised by a pi agent') that is clearly distinct from siblings like status, spawn, or steer. It scopes the tool to a narrow case (questions from pi extensions), so an agent can tell it apart from generic session tools. It stops just short of 5 because it never characterizes what an 'answer' does downstream beyond unblocking the caller.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear prerequisite chain: get `requestId` from `status`, and questions only exist for delegates spawned with `extensions: true`. That effectively tells the agent the condition under which this tool is callable. It doesn't state a when-not-to-use or name a fallback tool if no question is pending, so it falls short of explicit exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.