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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description adds a material behavioral trait: 'One call consumes one full-content preview for a free caller.' This quota/cost disclosure goes beyond the structured annotations and is highly relevant for an agent deciding whether to call the tool.

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 short sentences, each earning its place: the result statement, the usage guidance, and the quota warning. The most important selection guidance is front-loaded before the cost caveat, with no redundant 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?

The combination of description, annotations, and output schema gives an agent everything needed to select and invoke the tool: what it returns, when to use it, and one critical quota limit. The schema handles parameter and return-shape details, so the description does not need to repeat them.

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 67%, and the schema already documents query, intent, guideSlug, and subjectSlug. The description adds only light semantic context such as 'one question' and 'small set', while maximumTokens remains undocumented in both the schema and the description. A 3 reflects a balanced, minimally adequate contribution.

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 uses a specific verb ('Returns') and resource ('passages from Fiveable study guides') with a selection criterion ('most relevant to one question'). It clearly differentiates from fetching a full guide, so an agent can distinguish it from get_study_guide without opening schemas.

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?

It states explicit use cases: narrow explanations, research questions, and checking student notes. It also gives a direct alternative comparison by saying 'instead of fetching a full guide', which tells the agent when not to use the broader guide-fetching tool.

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