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

Annotations already declare read-only, idempotent, non-destructive, closed-world. The description adds genuine behavioral context beyond them: output is ranked by risk, each assumption is reformulated as a research question, and the tool refuses to simulate user answers. That last constraint is a meaningful behavioral trait not visible in the annotations.

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?

Two tight sentences with the core action front-loaded, followed immediately by the output shape and the boundary constraint. Zero filler.

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?

No output schema exists, so the description usefully sketches the return shape (risk-ranked assumptions, each as a research question). For a single-parameter read-only tool that is largely complete, though it could say more about input expectations or output format details.

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?

Only one parameter with 100% schema description coverage, so the schema already documents prd_text. The description restates the input as 'a PRD or design brief' but adds no format, length, or structural guidance beyond what the schema provides.

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?

States a precise verb+resource chain: reads a PRD or design brief and extracts unverified assumptions, ranked by risk, converted into decision-relevant research questions. The scope boundary 'Never simulates user answers' sharply distinguishes it from sibling critique/audit tools that evaluate rather than surface assumptions.

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?

Implies usage (call it when you have a PRD or brief and want unverified assumptions surfaced), and the negative scope 'never simulates user answers' tells the agent what it will not do. However, it never explicitly says when to prefer this over siblings like critique_experience or audit_copy, and doesn't state prerequisites.

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