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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds that it returns 'full details' but does not mention output shape, error cases, or whether 'full details' varies by type. With annotations covering the read-only nature, a 3 is fair — the description adds some but not rich behavioral context.

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?

Single sentence, zero wasted words, and the essential parameters are front-loaded. It is concise and readable.

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 2-parameter read-only fetch tool with full schema coverage and a readOnly annotation, the description is complete enough. It does not explain why type is needed or how the result is structured, but those are minor given the schema and the absence of an output schema requirement.

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 both parameters are already documented. The description only restates the idea of 'ID and type' without adding info beyond the schema. Baseline 3 is appropriate because the schema carries the load.

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 verb ('Fetch') and resource ('full details for a search result by ID and type'). It clearly distinguishes itself from the search tool by operating on search results, and from trip_get/trip_item_list etc. by requiring both id and type. This is a clear, differentiated purpose.

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 phrase 'for a search result' implies this tool is meant to be used after search, and the presence of sibling 'search' indicates the workflow. It does not explicitly name alternatives or exclusions, but the id+type pair and the mention of search results provide clear contextual guidance. Slight deduction for not explicitly saying 'use this after search, not for direct IDs'.

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