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

Annotations already cover read-only, idempotent, and non-destructive traits. The description adds valuable behavioral context: search returns contextual content with titles and links rather than full pages, and how to retrieve full content by appending .mdx. This goes beyond the annotation baseline.

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 concise sentences, each with a distinct role: purpose, usage guidance, and return-value/next-step behavior. The example is illustrative and not redundant. No fluff or repeated schema content.

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?

For a simple two-parameter search tool with no output schema, the description covers what it returns, how to use the results, and where to go for full content. An agent has all necessary context to call the tool correctly and handle the response.

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% and both parameters have descriptive text. The description does not add significant new information about the query or language parameters beyond what the schema already provides, so the baseline score of 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 uses a specific verb ('Search across') and names the resource ('DarkFunnels knowledge base') with clear scope. It distinguishes itself from the sibling query_docs_filesystem_dark_funnels by explicitly noting that full page content is obtained elsewhere.

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 gives explicit when-to-use conditions: answering questions about DarkFunnels, finding documentation, understanding features, or locating implementation details. It also provides a clear when-not-to-use directive, directing the agent to query_docs_filesystem for full page content, including a concrete example.

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