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

Annotations already establish that the tool is read-only, idempotent, and non-destructive. The description adds useful behavioral context beyond those hints, including the specific feature categories returned and that they come 'all with exact sequence positions' and under 'CC BY 4.0' from the UniProt Consortium. It does not cover edge cases like invalid accessions or source database distinctions, but the output schema and annotations cover the main safety profile.

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 efficiently structured: the first sentence states the core function, the second lists the returned feature types, and the third gives use cases and attribution. No sentence is wasted, and the most important information is front-loaded.

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 one well-documented required parameter, an output schema, and strong annotations. The description fully contextualizes the tool's purpose, feature coverage, positioning, and licensing, so an agent has enough information to invoke it correctly.

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% for the single parameter, and the schema already includes examples and a clear definition of the accession parameter. The tool description confirms the resource is keyed by UniProt accession but does not add meaningfully new parameter-level detail beyond what the schema provides.

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 opens with a specific verb and resource: 'Get sequence-level annotations and functional features for a protein by UniProt accession.' It enumerates concrete feature types (active sites, binding sites, signal peptides, transmembrane regions, disulfide bonds, PTMs, etc.), making the tool's role clear and distinguishing it from siblings like science.uniprot.entry and science.uniprot.search.

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 usage context by stating it is 'Essential for structural biology, drug target analysis, and protein engineering workflows.' It does not explicitly name alternative tools or state when not to use it, but the use case and functional scope are clear enough for an agent to select this tool appropriately.

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