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

Annotations already indicate readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: it should be written in the traveller's language, grounded in actual trip events, and a forced ending is worse than none. This goes beyond annotations and helps the agent produce appropriate content.

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 concise and front-loaded with the core purpose. Each sentence adds value: the primary action, the contrast with summary, the timing requirement, and the quality guidance. No wasted words, and it flows logically.

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 three parameters are fully documented in the schema and the description explains the tool's role and usage conditions, it is largely complete. It doesn't explicitly mention the clear parameter for removing a closing, but the schema covers that. The description gives enough conceptual context for an agent to decide when and how to invoke it.

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 100%, so all parameters (text, clear, trip_id) are well-documented. The description does not add any parameter-specific semantics beyond the schema, but it does hint at the 'clear' concept via 'leave it out' (though it doesn't explicitly link to the parameter). Baseline of 3 is appropriate given full schema coverage.

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 writes the closing passage for a trip's page, using a specific verb ('write') and resource ('closing passage'). It explicitly differentiates this from a summary, noting the summary opens the page while the closing comes after the whole journey is seen, which distinguishes it from sibling tools like set_trip_head or set_trip_theme.

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 provides clear context on when to use it: write it once the timeline is finished, and skip it if nothing comes to mind to avoid a forced ending. It also explains the distinction from the summary, which guides when not to use it for that purpose. However, it doesn't name other sibling tools like set_trip_head or set_trip_theme, but the summary contrast is a strong enough alternative.

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