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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description does not need to restate safety. It adds meaningful behavior beyond annotations: it returns only a small set of passages rather than a full guide, and it discloses that one call consumes a full-content preview for free callers. This context helps an agent predict cost and granularity.

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?

The description is three sentences with no filler: it states the output type, scope, intended use cases, an alternative, and a cost implication. The most important information is front-loaded before the usage guidance.

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?

Given the rich input schema, annotations, and existing output schema, the description covers the essential decision-making context: what the tool returns, when to use it, what it avoids, and its cost. It could name the alternative tool explicitly, but the phrase 'fetching a full guide' is clear in the context of the sibling tool list.

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 inline descriptions for query, intent, guideSlug, and subjectSlug already carry most of the meaning. The tool description reinforces the notion that query is a single question and that sections are a small set, but it does not substantially clarify maximumSections or maximumTokens beyond what their names, defaults, and constraints imply.

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 clearly states the tool returns 'a small set of passages from Fiveable study guides' relevant to 'one question,' which identifies the action, resource, and scope precisely. It also distinguishes itself from fetching a full guide, which sets it apart from related tools like get_study_guide.

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 description explicitly says to use this tool 'for narrow explanations, research questions, and checking student notes instead of fetching a full guide,' providing both positive use cases and an alternative. It also adds a cost constraint about consuming a full-content preview, which helps an agent decide whether to invoke it.

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