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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context beyond annotations by stating the $0.10 cost and API key requirement. It does not describe rate limits or error behavior, but the read-only annotations reduce the burden.

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 efficiently front-loaded with the core result, followed by a compact parenthetical covering cost and authentication. Every word contributes necessary information with no redundancy.

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 simple read-only tool with one parameter and an output schema, the description conveys the essential result and operational requirements. It is slightly thin on parameter details and tool differentiation, but the output schema and annotations fill most gaps.

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 input schema has a single required trip_id parameter with no description, and schema description coverage is 0%. The description does not mention trip_id or clarify its format or provenance, so the agent must infer meaning from the parameter name alone. The description fails to compensate for the absent schema documentation.

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 identifies the resource as a 'Single trip' and specifies its contents as 'linked places and people.' This distinguishes it from the sibling tool get_trips, which returns multiple trips. The action verb is implied by the title rather than stated in the description, keeping it from a 5.

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 use when a single trip with associated places and people is needed, but it provides no explicit when-to-use guidance or comparison with alternatives like get_trips. The selection is left mostly to inference.

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