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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely new behavior: the API returns all expenses, filtering happens client-side here, and the reply is truncated at `limit` and announces that truncation — exactly the kind of detail an agent needs to interpret a short result list.

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 compact sentences that front-load the resource identity and then the filtering/truncation behavior. No filler, and the most decision-relevant fact (filtering is local, not server-side) is stated early.

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 read-only list tool with no output schema, the definition covers scope, filtering, and truncation signaling adequately. Return record fields are unspecified, but that is a minor gap for a listing endpoint whose sibling list tools behave similarly.

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 75%, and the one undocumented parameter, `matter_id`, is given meaning by the phrase 'filter here by matter'. The date filters and `limit` are already explained in the schema, so the description modestly but meaningfully extends the structured data.

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 the resource precisely ('expenses logged against matters') and states what the call returns, which no sibling tool covers. It is clear but does not explicitly contrast with other list tools, relying on the unique resource to differentiate.

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?

It indicates when to use the local filters ('filter here by matter and date range') versus the unfiltered API result, which is a useful cue. However, there are no explicit exclusions, prerequisites, or named alternatives beyond the implicit 'no filtering is done server-side' note.

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