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

Annotations already declare non-readOnly, non-destructive, idempotent, open-world behavior, so the bar is lower. The description adds real context beyond them: it does not recheck route safety, it requires an authenticated account plus explicit account consent, and it returns source/freshness metadata.

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 compact sentences with the key limitation front-loaded and units/metadata grouped in a second line. Every clause carries information; only the 'directions FROM' fragment is slightly cryptic.

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?

With no output schema, the description correctly notes it returns data plus source/freshness metadata. Combined with the auth/consent prerequisite and unit conventions, it covers most of what an agent needs for a nested-body mutation tool, though the individual updatable fields remain only in the schema.

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 description coverage is 0%, so the schema documents structure but no field meaning. The description compensates with unit conventions (ft, kt, s, F, mi) and a 'directions FROM' hint, but leaves the dozen body fields (to/via/from, name, notes, status, activity, etc.) semantically undocumented.

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 specific verb+resource ('Update specified trip fields') that clearly marks a partial-update operation, distinguishing it from save_my_trip and get_my_trip. It does not explicitly name the sibling it differs from, but the 'specified fields' phrasing implies PATCH semantics.

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?

'This does not recheck route safety' implies an exclusion (use check_route_conditions when safety validation is needed) and states an account/consent prerequisite. However, no alternative is named explicitly and there is no direct guidance on when to prefer this over save_my_trip.

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