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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the closing 'Read-only; changes nothing' mostly repeats structured data. The real contribution is disclosing the shape of the result — per-topic accuracy, answered counts, last-practiced timestamps, review-due totals, exam date, and suggested next steps — which matters because there is no output schema.

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 well-formed sentence, front-loaded with the core purpose and then the returned fields. The trailing read-only clause is redundant with annotations and could be dropped, but nothing else is wasted.

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 single-optional-parameter read tool with no output schema, the description is complete enough: it tells the agent what data comes back and that nothing is mutated. The missing piece is routing guidance — when to call this versus get_exam_overview or get_study_plan.

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%, and the single `exam` parameter's schema text already explains the id format and the save_study_settings fallback. The description adds no meaning beyond that, so the baseline 3 applies; it neither clarifies nor misleads about the parameter.

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?

The description gives a specific verb and resource (show the learner's readiness for one exam), and enumerates the dimensions returned: overall and per-topic accuracy, number answered, last practiced, review-due count, exam date, and next steps. It is clear what the tool does but never distinguishes it from siblings like get_exam_overview or get_study_plan, which likely overlap in subject matter.

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?

There is no when-to-use or when-not-to-use guidance, and no sibling is named as an alternative. An agent must infer from the phrase 'one exam (grade)' that the exam id matters, and must read the schema to learn that omitting it falls back to the saved grade. No prerequisites or preconditions are stated.

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