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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful behavioral context beyond that: it returns contextual content with titles and direct links, and clarifies that it does not return full page content, pointing to a filesystem command for that. This is meaningful extra information.

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 sentences, each earning its place: purpose, when-to-use, and output/alternative workflow. The embedded example (`head -200 /api-reference/create-customer.mdx`) is practical and not excessive. The description is front-loaded with the primary purpose before any secondary instructions.

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 one-parameter search tool with strong annotations, this description is complete. It explains what the search returns, how to get full content when needed, and which sibling to use. Nothing an agent needs to invoke the tool correctly is missing.

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 only parameter, query, is fully documented in the schema with the description 'Search query', so schema coverage is 100%. The tool description does not add parameter-level detail, but none is needed given the simple single-parameter design.

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?

States a specific action ('Search across the TheRundown API knowledge base') and enumerates what can be found: relevant information, code examples, API references, and guides. It also distinguishes itself from query_docs_filesystem by focusing on search results rather than full page content.

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?

Explicitly says when to use: 'Use this tool when you need to answer questions about TheRundown API, find specific documentation, understand how features work, or locate implementation details.' It also gives an explicit alternative for full content retrieval using query_docs_filesystem, including how to append `.mdx` to returned paths.

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