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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context beyond the schema: it notes the sequence is truncated to 'first 200 aa', lists the exact fields returned, and mentions the licensing (CC BY 4.0). This gives the agent a clear picture of what to expect. No contradiction with annotations.

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 moderately long but every sentence serves a purpose: it states the function, enumerates return fields, gives examples, and credits the source. The main action is front-loaded, and the field list is exhaustive without redundancy. It could be trimmed slightly, but it is well-structured and reader-friendly.

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?

With a single required parameter, complete schema coverage, an output schema present, and annotations covering safety, the description provides sufficient context. It explains what data will be returned and even notes the sequence truncation, which is a crucial detail for downstream use. It does not cover error cases (e.g., invalid accession), but for a lookup tool the description is adequately complete.

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% (the 'accession' parameter includes examples and notes that entry names are also accepted). The tool description adds concrete example accession numbers (P69905, P01308, P04637) with biological names, which helps disambiguate the format and illustrates valid identifiers. While the schema already covers the semantics, the examples provide extra clarity, so a slight bonus above the baseline of 3 is justified.

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 purpose: 'Get full annotation details for a protein by UniProt accession number.' It lists specific return fields (EC numbers, gene names, subcellular location, etc.) and provides concrete examples of accession numbers with their biological identities (P69905 = hemoglobin alpha chain). This is a specific verb+resource with rich detail, distinguishing it from sibling tools like search or features by focusing on 'entry details.'

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: you need a UniProt accession number, and it gives examples of how to format them. However, it does not explicitly state when to choose this over siblings such as 'science.uniprot.search' (for finding accession numbers) or 'science.uniprot.features' (for specific feature details). There is no 'if you don't have an accession, use search' guidance, so the agent is left to infer the workflow. This is adequate but leaves room for confusion.

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