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

The 'Closed-world' sentence essentially restates the supplied openWorldHint=false annotation rather than adding new behavioral information. It says nothing about ordering, pagination, whether the trip owner is included in results, permission requirements, or what happens when the trip is inaccessible — all of which the annotations do not cover.

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 core purpose is front-loaded in one tight sentence with zero filler. The second sentence is largely redundant with the annotations, which is a minor efficiency loss but not a structural problem.

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?

This is a simple one-parameter read tool; safety hints are covered by annotations and return values by the existing output schema, so the description needn't carry those burdens. The remaining gap is small — no guidance on obtaining the trip_id or on behavior when access is denied.

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?

There is a single required parameter with 100% schema description coverage ('Tripsy trip id.'). The description adds no meaning beyond that — it does not say where a trip_id comes from (e.g., tripsy_trips_list) or what format it takes, so the baseline 3 applies.

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 names a specific verb and resource ('List collaborators') and adds scope detail the name alone doesn't convey: pending invitations are included. Against siblings like tripsy_collaborators_invite/update/delete, an agent can immediately tell this is the read-only enumeration path.

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?

Usage is implied by the verb and by the necessary trip_id, so an agent will infer it should be called to inspect who has access to a trip. However, there is no explicit when-to-use or when-not-to-use statement, and no mention of related alternatives (e.g., invite to add a collaborator).

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