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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety bar is low. The description still adds real behavioral context beyond them: the has_dates authority rule for interpreting undated trips, the guarantee that owner/guests/has_dates/starts_at/ends_at are always returned, and the deleted-records behavior.

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?

Three tight sentences, front-loaded with scope, then the has_dates rule, then capabilities, then safety. The only near-redundancy is the closed-world safety line restating openWorldHint=false, but it is short and reinforces scope.

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 an output schema present, return values need no explanation, and the description covers filtering, field selection, deleted records and the undated-trip edge case. The only gap is the absence of explicit sibling routing, which is minor for a list tool with full schema coverage.

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 coverage is 100%, so baseline is 3, but the description adds meaning the schema does not: it explains that has_dates overrides starts_at/ends_at, and that certain fields are force-included regardless of the fields allow-list. That is genuine semantic value beyond the parameter docs.

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 and resource ('List Tripsy trips') plus a precise scope: owned trips and shared trips where the current user has is_travelling permission. This implicitly separates it from trips_following_list, but it never names that sibling, so the differentiation is inferential rather than explicit.

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 scope sentence tells an agent which trips are returned, which implies when to use it, and the has_dates rule gives a concrete usage constraint. However, there is no explicit when-not guidance and no named alternative (e.g. trips_following_list for followed trips), leaving the routing decision partly to inference.

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