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

Annotations declare readOnlyHint=true, and the description usefully supplements that with the page size (20 per page) and sort order (newest first), which matter for pagination behavior. It doesn't discuss rate limits or total-count behavior, keeping it just under 5.

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?

One dense sentence that front-loads sort order, page size, and filters, then states the required-parameter rule and the API endpoint. No filler.

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 description covers filtering, ordering, pagination size, and the endpoint. It omits what a certificate record contains and how to page through results (e.g. stop conditions), which is a minor residual gap.

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%, so the baseline is 3, but the description adds a genuine semantic constraint not expressed in the schema: the course_id/user_id mutual requirement. It also clarifies the filter combination is conjunctive in spirit ('and/or').

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 ('Certificates awarded ... for a course and/or a user') and adds scope detail (newest first, 20 per page) plus the backing endpoint. An agent can immediately distinguish it from siblings like list_course_users or get_user_course_progress.

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?

Gives an explicit precondition — 'at least one of course_id or user_id is required' — which is a real routing rule since the schema marks zero parameters required. It doesn't name alternative tools for adjacent questions (e.g. per-user course progress), so it stops short of 5.

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