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

The description goes beyond the readOnlyHint annotation by disclosing exactly what the output includes (measurement, importance, limits, time series, canonical source URL) and clarifying default segment behavior. This provides rich behavioral context without contradicting the read-only nature.

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 two sentences, front-loads the core purpose, and packs useful detail without fluff. Every phrase adds value, from the list of output components to the segment type examples.

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?

Given the read-only nature, no output schema, and two simple parameters, the description provides a complete picture: what is returned, what parameters do, and possible segment values. It is sufficient for an agent to 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?

The schema already describes both parameters with examples (metric id, segment slug). The description adds further meaning by explaining segment defaults and naming country/company cut examples, enriching the understanding beyond the schema.

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 clearly states the tool returns 'full detail for one Quiet Failures base rate segment', listing specific content like the figure, confidence interval, measurement approach, and source URL. It specifies the metric and segment parameters, and the scope ('one segment') distinguishes it from list_base_rates while the detail level separates it from find_base_rate.

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?

The description implies usage for retrieving comprehensive details on a single segment, noting the default segment and available cut types. It does not explicitly name alternative tools or exclusion criteria, but the context is clear enough for an agent to know when to invoke this tool.

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