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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, and the "Closed-world" sentence simply restates that last flag rather than adding new information. Nothing is said about pagination, result ordering, behavior when the trip_id is unknown or inaccessible, or how the `deleted` and `fields` options alter the response.

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 short sentences, nothing padded or redundant in structure, and the resource is front-loaded. The middle clause "Supports common list filters" is vague filler that conveys less than its word count suggests, keeping it from a 5.

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 7 parameters, a required trip_id, and multiple sibling list/show tools, an agent needs to know scope (single trip only?), whether deleted records appear by default, and how this relates to tripsy_expenses_show. Annotations and the output schema cover safety and return shape, but the description leaves the invocation context largely unexplained.

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 the schema already explains every one of the 7 parameters, including deleted, updated_since, and fields/fields_exclude. The description's "common list filters" adds no concrete meaning (it does not enumerate which filters exist or note that trip_id is required), leaving it at the high-coverage baseline.

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 fragment "Trip expenses." names the resource and "Supports common list filters" implies a list operation, but no explicit verb+resource statement is given; an agent infers 'list' from the title and tool name rather than the description. It does not distinguish this from siblings like tripsy_expenses_show (singular fetch) or tripsy_activities_list beyond the resource noun.

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?

No guidance on when to use this versus tripsy_expenses_show, tripsy_trips_list, or other list endpoints, and no prerequisites (e.g., needing a valid trip_id, or access to the trip). The only cue is "common list filters," which does not say which situations call for them.

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