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

The description goes beyond the annotations by disclosing overwrite behavior (recording twice replaces earlier wording, pinned claims are left as is), the required 'act' scope, and the return payload (top of board with move ids). readOnlyHint=false is consistent with the described write behavior, and destructiveHint=false is not contradicted.

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?

The description is dense but efficiently organized with 'WHEN' and 'WHAT COMES BACK' markers, front-loading the core purpose first. Every sentence carries distinct information—trigger, exclusions, auth, overwrite behavior, return shape—so nothing is wasted despite the length.

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 tool with no output schema, the description compensates by specifying the return value, required scope, overwrite semantics, and exact inclusion criteria. All five parameters are covered by the schema, and behavioral dependencies (pinned claims) are disclosed. No significant gap remains for an agent to decide and invoke correctly.

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?

With 100% schema coverage, the schema already documents each parameter. The description adds meaningful semantic framing—number must be a real measurement, never an estimate, and the caveat must accompany it ('a number without its caveat is what this library exists to prevent'). This clarifies relationships between parameters beyond their individual schema descriptions.

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 uses a specific action ('Put one measured number... into the claim library') and clearly scopes what belongs: only measured numbers the founder will defend. It distinguishes this tool from similar record-style siblings by defining its exact input conditions, even though it doesn't name the sibling explicitly.

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?

WHEN gives a concrete trigger (real measurement lands, founder says they would defend it) and the NEVER-list provides explicit exclusions (estimates, projections, rival figures, inferred data). It lacks an explicit pointer to alternative tools like record_insight, so routing is strong but not fully complete.

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