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

Annotations already declare readOnlyHint, idempotentHint, and no destructive actions, so the description need not repeat safety. The description adds value by specifying the retrieval granularity (single item) and the included content sections, which goes beyond the schema's slug parameter. It does not detail what happens if the slug is not found, but this is minor given the safety coverage.

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 a single, well-structured sentence that front-loads the action and key details. It doesn't waste words, and the focus on content sections is efficient and informative.

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 description is sufficient for an agent to call this tool correctly: it identifies the input (slug) and the output content areas. The output schema exists, so return-value details are not required. The description could specify error behavior, but that is a minor gap given the simple single-parameter tool and safety annotations.

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?

The schema fully covers the slug parameter with a clear description and an example URL structure. The description does not add new semantic meaning beyond what the schema provides, but with high coverage, that is acceptable. Baseline 3 is appropriate because the schema does the heavy lifting.

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 fetches a single Flamel case study by slug announced with a specific verb ('Fetch'). It lists the key content sections (challenge, solution, results, quotes), which is specific and helps the agent know what to expect. It distinguishes from siblings like list_case_studies by implying a single item lookup.

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 states the use case: fetching a single case study by slug. This clearly implies it is for when a specific case study is needed, contrasting with list_case_studies. It does not explicitly mention when not to use it or name alternatives, but the context is clear enough for an agent to choose correctly.

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