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

With no annotations, the description must carry the full burden. It discloses the core behavior (full-text search with filters) and the corpus size, but does not mention output format, pagination, read-only status, or any side effects. For a search tool, this is minimally adequate but lacks depth.

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 two concise sentences, front-loaded with the core purpose and followed by a brief note on filters. Every word earns its place; there is no redundancy or fluff.

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 tool has 4 parameters, no output schema, and no annotations, so the description needs to provide more context about expected results and parameter behavior. It omits what the return value looks like, how limit works, and any constraints like minimum query length, making it insufficient for a complete understanding.

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 explicitly mentions the SUS and trials filters, and 'full-text search' implies the query parameter. However, the 'limit' parameter is not addressed in the description, and the schema provides no descriptions either, leaving a gap.

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 performs full-text search over a specific set of 10,468 rare diseases, and mentions the SUS/trials filters. This specific verb+resource+scope distinguishes it from sibling tools like find_diseases_by_phenotypes or search_phenotypes.

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 implies usage for searching rare diseases when SUS coverage or active trial filters are needed, but it does not explicitly state when to use this tool versus alternatives or provide exclusion criteria. The filter support gives context, but no direct comparison to siblings.

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