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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavior: one month per call, the current month being partial/incomplete until closed, and an explicit auth requirement (Cotlet API key with access to this app). It stops short of describing pagination or response shape, but adds real value over the annotations.

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?

Front-loaded with the resource and content, but the second sentence largely restates the first — channel/course/refunds/tax-withheld are enumerated twice in consecutive sentences. That redundancy costs it a higher score even though the remaining sentences (cadence, freshness, auth) each earn their place.

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 usefully explains what the report returns (total earnings plus channel/course splits), and it flags the partial-current-month caveat and the auth requirement. Only minor gaps remain: no note on pagination or history limits across months. Adequate and nearly complete for a single-parameter read-only report.

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% with a single documented 'month' parameter (YYYY-MM), so the schema carries the semantics. The description reinforces this with 'one month per call' but adds no format or range detail beyond the schema, making the baseline 3 appropriate.

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 (get revenue report) and resource (monthly earnings), plus the exact decomposition of the output: revenue by channel, by course, refunds, and tax withheld. An agent can immediately tell this is a Udemy monthly revenue reporting tool without opening the schema.

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?

Provides one operating constraint ('one month per call') and a data-freshness caveat (the current month is partial until Udemy closes it). However, it never explains when to reach for this tool versus a sibling like udemy_get_course_performance or udemy_list_courses, so routing guidance is only implied.

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