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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's a safe read operation. The description adds behavioral detail beyond annotations: it specifies pagination, the exact fields returned, filtering options, and data licensing (CC BY 4.0). It also mentions that partial names and genus-level queries are supported, which is useful operational context.

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 well-structured: it opens with the core purpose, then details the return payload, filtering options, downstream usage, and citation. It is somewhat verbose with background about COL's comprehensiveness and licensing, but each sentence serves a purpose and the critical operational details are front-loaded. It is not overly long for a tool that needs to explain pagination and follow-up actions.

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 description covers all essential aspects for an agent to call the tool correctly: what it does, what it returns (even though an output schema exists, the description explicitly lists fields), how to paginate, how to filter, how to chain with other tools, and the licensing/citation requirement. It is comprehensive and self-sufficient.

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 coverage is 100% and each parameter has a description. The description adds value by providing concrete query examples ('Homo sapiens', 'Pinus sylvestris', 'oak') and noting that partial names and genus-level queries are supported, which is not in the schema. It also reinforces the filtering semantics for rank and status, slightly exceeding the baseline for high 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 states a specific verb ('Search'), a clear resource (Catalogue of Life), and the scope (species, genera, families, other taxa by scientific or common name). It also lists what is returned (taxon ID, scientific name, rank, status, classification, vernacular names) and differentiates from sibling tools by mentioning col.species.detail and col.species.children, making it distinct.

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 gives clear context: it's a search tool, supports filtering by rank and status, and explicitly tells the agent to use the returned taxon ID with col.species.detail or col.species.children for further steps. However, it does not mention col.species.suggest, a sibling search-related tool, so it doesn't fully cover all alternatives. Still, the guidance is practical and actionable.

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