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

Annotations already declare readOnlyHint=true, so the safety profile is covered by structured data. The description adds that results are paginated and maps to the upstream REST call, which is useful context, but it does not disclose pagination limits, ordering, or default page size behavior beyond what the schema already implies.

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 tight sentences with zero filler; the core action and filters are front-loaded and the pagination/endpoint note follows.

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 no output schema, the description could say more about the returned collection shape, but for a read-only listing tool with fully documented parameters and a readOnlyHint annotation, the filtering and pagination coverage is sufficient for correct invocation.

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% with all nine parameters individually documented, so the schema carries the parameter burden. The description's filter list ('user, client, project, date range, billed status, updated-since') mirrors the schema without adding format, default, or interaction details.

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 expenses') and enumerates the available filter dimensions, so an agent knows exactly what the tool returns. It does not explicitly contrast itself with the other harvest_list_* siblings (time entries, invoices, projects), though those target different resources so ambiguity is low.

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 description implies when the tool is useful ('optionally filtered by...'), but gives no explicit when-to-use/when-not guidance, no mention of prerequisites (e.g. needing an account token), and no routing to an alternative for cross-resource retrieval.

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