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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds specific behavioral detail: that an incomplete index produces an error rather than a seemingly exhaustive response, and that fetched sources must be relied upon. This goes beyond the openWorldHint and provides actionable guidance.

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 four sentences long, with no wasted words. Each sentence adds value: the purpose, the scope limitation, the fetch instruction, and the error behavior. The critical information is front-loaded, making it easy for an agent to parse quickly.

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 tool's simplicity (one parameter), the presence of an output schema, and rich annotations, the description covers the essential aspects: scope, return type, and error behavior. The only notable gap is the lack of differentiation from mrx_search_guides, but this is not critical for calling the tool correctly.

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?

With 0% schema description coverage for the single 'query' parameter, the description must carry the burden of explaining parameter semantics. It only implies that 'query' is the search term through the tool's purpose, but does not elaborate on format, constraints, or how the query is interpreted. This is insufficient given the low coverage.

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 verb 'Search' and the resource 'public MRX educational guides,' and specifies that it returns citable canonical document IDs. However, it does not differentiate from the sibling tool mrx_search_guides, which likely serves a similar purpose, so it falls short of a 5.

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 provides clear context: it is for public guides only ('No private cases') and instructs the agent to 'Fetch each source before relying on it.' It does not explicitly name an alternative or specify when to use this tool versus mrx_search_guides, but it gives enough context to guide usage in most cases.

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