lookup_protein

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

Beyond the readOnly/openWorld annotations, the description explicitly discloses that the tool is not implemented and will return error code 'unsupported' (E8). This is a critical behavioral trait an agent cannot infer from the schema or annotations, and it is stated precisely.

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-loads the purpose, and then adds the essential unsupported warning without wasted words. It is appropriately sized for the tool's stub nature.

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 adequately covers purpose and the critical unsupported status, and an output schema exists to fill return-value details. However, it leaves gaps around input identifier format and does not route the agent to a working sibling tool, so completeness is adequate but not strong.

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 schema coverage at 50%, the description needed to clarify the required 'protein' parameter, but it only says 'Protein identity...' and does not specify accepted identifier types (e.g., UniProt accession, gene name). The 'sources' parameter is already described in the schema, so the description adds little parameter-level meaning.

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 the resource (protein) and data source (UniProt and cross-references), and 'identity, function and features' makes the lookup intent clear. It is distinguishable from sibling lookup_gene and lookup_variant by the protein focus, though it lacks an explicit verb in the description itself.

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 'Not implemented in this build' warning tells the agent that invoking this tool will produce an unsupported error, which is a meaningful negative usage signal. However, it does not provide positive when-to-use context or name an alternative tool for protein lookups, so the guidance is only partial.

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