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

Annotations already establish read-only/idempotent/non-destructive, and the description adds real behavioral context: results are one-line teasers plus a link, and the quiz is interactive/scored in-browser so the agent must not answer questions itself. That is exactly the kind of non-obvious behavior an agent needs.

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?

Three sentences, each with a distinct job: what the tool is, how to invoke the optional filters, and how to handle results. Front-loaded with the resource and zero 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?

With no output schema, the description still conveys the return shape (teaser line + link) and the crucial interaction rule for using results. For a simple optional-filter list tool, nothing needed to call it correctly is missing.

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% with per-parameter descriptions, so the baseline is 3. The description adds combination semantics ('pass query and/or category'), though it says 'both arguments' when three exist, so it neither compensates for nor meaningfully exceeds the schema.

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+resource ('Find ... quizzes'), names the domain topics, and adds distinguishing detail (ten-question, instant explanations, certificate) that separates it from sibling article/calculator tools.

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?

Explicitly says both arguments are optional and how to browse vs narrow ('omit everything to browse, pass query and/or category to narrow'), plus a clear when-to-use directive to send the user to the URL. It does not name sibling tools as alternatives, which keeps it just short of a 5.

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