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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds value by disclosing what content is included ('bounded Markdown content, update metadata, primary-source review details') and explicitly excluding access to private learner data, which goes beyond the structured annotation fields.

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, front-loaded with the core action, and no filler. Every sentence contributes meaningful detail (content scope, privacy boundary).

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 an output schema present, the return value is already covered. The description provides enough about data scope and privacy for a simple retrieval tool, but the missing region semantics and lack of guidance toward search_driving_guides make it slightly incomplete.

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 0%, so the description must compensate. It mentions 'by slug' but does not explain the 'region' parameter at all, nor does it clarify how region interacts with slug selection. The agent gets little semantic guidance beyond the schema's enum and pattern constraints.

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 ('Retrieve') and resource ('one published Drivings guide by slug'), clearly distinguishing it from sibling tools like search_driving_guides. It also names content categories ('bounded Markdown content, update metadata and primary-source review details'), sharpening the scope.

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 context is clear: this tool is for retrieving a single known guide by slug, and the note 'It does not access private learner data' sets expectations. However, it does not explicitly mention alternatives like search_driving_guides for finding slugs, so it falls 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.