reactome_search_facets

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

No annotations are provided, so the description carries the burden of disclosing behavior. It explains that the tool returns facets globally or per query, but does not disclose what the return structure looks like, any rate limits, or explicitly confirm read-only behavior. For a simple getter, this is adequate but not rich.

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 a single concise sentence that conveys the purpose, scope, and optionality. It contains no fluff and is front-loaded with the action.

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 is simple (one optional parameter, no output schema), and the description covers its core behavior. However, without an output schema, the description should ideally explain the shape of the returned facets or how they can be used. This gap prevents a higher score.

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%, so the baseline is 3. The parameter 'query' is already described in the schema as 'Search term (optional, returns global facets if omitted)'. The tool description adds no new meaning beyond the schema, thus no bonus is warranted.

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's function: 'Get available facets (filters) for search results, either globally or for a specific query.' It uses a specific verb ('Get') and resource ('facets for search results'), and distinguishes itself from sibling search tools by focusing on metadata (facets) rather than actual search results.

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 context – it can be called without a query for global facets or with a query for query-specific facets. However, it does not explicitly state when to prefer this tool over other search-related siblings (e.g., reactome_search, reactome_search_paginated) or provide exclusions.

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