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

Annotations already declare readOnlyHint=true, and the description adds essentially nothing behavioral beyond mapping to 'GET /api/projects'. The important trait here — Paymo has no pagination and results past the limit are silently truncated — lives only in the schema's limit field, not in the description.

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, front-loaded with the verb and resource, with zero filler. The field enumeration is slightly long but defensible given there is no output schema.

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, listing the returned fields is genuinely useful, and the endpoint reference grounds the tool. The remaining gap is that pagination/truncation behavior for a list tool is never surfaced in the description itself.

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 all eight filters (limit, where, active, include, user_id, billable, client_id, manager_id) are already documented in the schema. The description's parenthetical lists output fields rather than input parameters, so it adds little parameter meaning beyond the schema 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?

States a specific verb (List) and resource (projects), and enumerates the returned fields (id, name, code, client_id, active, billable, budget_hours, users, managers), which clearly separates it from single-project tools like paymo_get_project. It stops short of naming that sibling explicitly, so it is clear but not maximally differentiated.

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?

'optionally filtered' implies the tool can be narrowed but gives no explicit when-to-use guidance, no mention of the alternative paymo_get_project for a single project, and no statement about which filters compose. Usage is inferable from the schema but not stated.

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