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

Annotations already declare the safe-read profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower. The description still adds value beyond them: it discloses newest-first ordering, that Udemy caps monthly coupon creation per course, and that the response includes remaining quota plus the Cotlet API key requirement.

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 core purpose, but wasteful: the returned fields ('type, price, redemptions and expiry') are listed twice, and the monthly-limit rationale is restated in two consecutive sentences. Trimming the duplication would tighten it without losing information.

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 two-parameter read tool with no output schema, the description covers the return fields, ordering, the monthly quota caveat, and the auth prerequisite. It is nearly complete; the only real gap is any hint about pagination or result size limits.

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 both course_id and active_only are already documented in the schema. The description reinforces that the scope is 'one course' but adds no syntax or format detail and never mentions active_only, so baseline 3 is correct.

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 ('Lists') and resource ('the coupons of one course'), and enumerates the returned fields (code, type, price, redemptions, expiry). An agent can immediately distinguish this from the sibling udemy_create_coupon and the other Udemy list tools 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?

The description makes clear it operates on a single course and requires a course-scoped API key, which implies the course_id prerequisite. However, it never states when to prefer this over alternatives or any exclusions, so usage is only implied rather than spelled out.

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