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

With no annotations, the description must carry behavioral disclosure. It states the core action and outcome but omits network implications, parameter dependencies, error behavior, or that it discards other parameters. The schema hints at discarded parameters, but the description itself does not reveal these traits.

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?

A single direct sentence with no filler. The action is front-loaded and the sentence is appropriately sized for the tool's narrow focus.

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 is severely incomplete for a tool with 9 optional parameters. It does not explain how to specify the target URL, what 'group counts' means, whether the tool actually makes a network request, or what happens with other parameters. Without an output schema or more context, an agent cannot reliably invoke 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?

Schema coverage is 100%, so the baseline is 3, but the parameter descriptions are generic and unrelated to robots.txt (e.g., 'City name for a public weather hint'). The tool description does not clarify which parameter actually targets the robots.txt URL, leaving the mapping ambiguous. It fails to add meaning beyond the schema.

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 action ('Fetch a public robots.txt') and a distinct result ('return group counts only'). This is clear and distinguishes it from sibling web tools like web-fetch or fetch-status, which do not mention robots.txt parsing or group counts.

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 no context on when to use this tool versus alternatives, no exclusions, and does not mention any conditions for use. An agent has no guidance on whether to pick this over web-fetch or other URL tools.

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