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

readOnlyHint=true already covers the safety profile, so the description's added value is limited. It does disclose the returned data fields (completion %, score, time, certificate) but doesn't say what happens for a non-enrolled user, whether an error or a null status is returned.

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 plus the endpoint path, front-loaded with the resource ('One user's status in one course'). The field enumeration is compact but slightly list-like.

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 field enumeration is the most useful part of the description and it's included. Missing only the non-enrolled/empty-result behavior, which matters for a progress lookup.

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% and both params are documented with types and constraints in the schema. The description adds only the query-string form user_id=&course_id=, which is marginal value, so baseline 3 applies.

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 precise verb and resource with exact scope: one user in one course, plus the endpoint. It's clearly not a list tool, so the agent won't confuse it with list_user_courses or list_course_users, though no sibling is named explicitly.

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?

Usage is implied by 'one user's status in one course' rather than stated. There's no explicit 'use this when you need X, use list_course_users when you need Y' routing guidance.

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