search_mesh_descriptor

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

The description discloses critical behavior: returns JSON-formatted string, on failure does NOT raise but returns a plain string starting with 'Error:' and instructs to check before parsing. This adds value beyond the readOnlyHint and openWorldHint annotations, which do not cover error handling or return format.

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 sentences, front-loaded with the purpose and followed by a crucial error-handling note. Every sentence earns its place with no filler.

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 8 parameters with many undocumented aliases, and the description does not explain how to construct a query or which parameter takes precedence. While the error handling and return type are covered, the overall parameter semantics remain incomplete, making it hard for an agent to use correctly without additional inference.

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 description only references 'query' generically, while the schema has 8 parameters with only 25% coverage. It does not explain the relationship between the many alias parameters (name, term, search, keyword, etc.) or how they should be used, failing to compensate for the low schema 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 'Search for MeSH ID by query', specifying the verb, resource, and input. This distinguishes it from sibling entity search tools like search_uniprot_entity or search_pdb_entity by targeting MeSH specifically.

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 that this tool is for MeSH ID lookup, making the primary use case obvious. It does not explicitly mention alternatives or exclusions, but the MeSH-specific purpose gives sufficient guidance for when to use it.

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