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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description's added value is the dual accepted input form (set_id or official code) and the two-part response shape, but it says nothing about error behavior for an unknown code or whether both exam forms are always resolvable.

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 sentences, no filler; the payload description leads and the parameter clarification follows, so the most decision-relevant content is front-loaded.

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?

An output schema exists, so return values needn't be spelled out; the description still sketches them, which aids tool selection. With annotations covering the safety profile and the sole parameter explained, only minor edge-case behavior is unaddressed.

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 0% and the schema only labels the field 'Exam', so the description carries the burden — and it does, explaining that `exam` accepts either a set_id from search_exams or an official exam code. It omits format examples (e.g., typical code shape) or case/format rules, keeping it just below top marks.

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 ('Describe one exam') and enumerates the exact payload: official code, question count, fee, domain weights, plus practice-set size, free questions, price, and timed mock. The scope (one exam, both vendor and practice data) is distinct from list_exams/search_exams and from get_practice_questions.

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?

Tells the agent how to obtain the required input ('a set_id from search_exams or an official exam code'), which implicitly routes the agent through search_exams/list_exams first. It stops short of explicit when-not-to-use guidance or naming get_practice_questions as the alternative for drilling into questions.

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