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

Annotations declare a non-destructive mutation, and the description adds real context beyond them: progress in every course is kept, so the agent knows switching is reversible and lossless. It does not say what happens to in-flight sessions or whether the previous course remains accessible, keeping it short of a 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?

Two short sentences with the action front-loaded and the state-preservation guarantee immediately after; nothing is wasted or redundant.

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 one-parameter mutation with annotations and no output schema, this covers the action and its key side effect. A brief note on what the call returns (e.g., the new current course) would make it fully self-sufficient.

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?

Only one parameter exists and the schema fully documents it ("An examId from list_courses" at 100% coverage); the description adds no format or constraint details beyond that. Baseline 3 applies since the schema carries the semantic load.

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: it makes another exam the player's current course, which also reconciles the examId/course naming mismatch. It is clearly distinguishable from list_courses (the source of examId) and other siblings, though it never explicitly names the resulting course object.

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 phrase "another exam" implies usage only when a current course already exists, and the schema points to list_courses as the source of examId. There is no explicit when-not guidance, no mention of alternatives, and no stated prerequisite such as course availability.

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