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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is consistent with read-only behavior. The description adds only that it lists 'valid' sectors, implying a controlled vocabulary. It does not contradict annotations but also does not provide significant behavioral detail beyond what annotations already convey.

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, succinct sentence that front-loads the verb and resource. There is no fluff, and every word contributes to clarity. It is an example of concise and well-structured tool documentation.

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?

For a tool with no parameters and an existing output schema, the description is fully sufficient. It explains the tool's purpose, and the output schema provides the return structure. No additional information is needed for an agent to call this tool 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?

The tool has zero parameters, so schema coverage is trivially 100%. Per the rubric, a baseline of 4 is appropriate for no parameters. The description does not need to explain parameters and does not attempt to, so it does not detract from the baseline.

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: listing valid token sectors for token discovery filters. The verb 'List' and resource 'token sectors' are specific, and the purpose ties directly to token discovery, distinguishing it from sibling tools like token_discovery_screener that likely consume these sectors.

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 context that the tool's output is intended for token discovery filters, implying its use case. However, it does not explicitly mention when to use it versus alternatives or when not to use it, and it names no sibling tools. The context is sufficient for an agent to infer usage but lacks explicit exclusions.

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