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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint safety. The description adds useful behavioral context beyond those: it returns only 'titles and canonical references rather than full content' and notes that the search is cheap. This helps an agent set expectations about cost and output shape.

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, no filler. The main action and scope come first, followed by the use case and a key return-value caveat. Every sentence earns its place.

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 presence of a full output schema, rich annotations, and a 100%-covered input schema, the description provides the missing context: the cross-cutting search scope, when to prefer it, and the lightweight return format. Nothing essential is left for the agent to infer.

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%, so each parameter is already documented. The description adds general keyword-search framing, but it does not add meaning beyond the schema for query, limit, intent, or subjectSlug. Baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Keyword search across every Fiveable study guide, unit, subject hub and key term.' This clearly identifies the tool's scope and distinguishes it from sibling get_ and list_ tools that operate on specific known resources.

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 gives explicit guidance about when to use the tool: 'Suitable when the relevant subject or guide is not known.' It implies the alternative is to use more targeted tools when a known resource exists, though it does not name those alternatives explicitly.

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