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

No annotations are provided, so the description carries the full burden. It does disclose that only group counts are returned, but it does not explain how the robots.txt URL is derived, what failures look like, whether network access is required, or what 'group counts' means in practice.

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, tight sentence with no filler and the output constraint is front-loaded. It is concise, though slightly under-specified for a tool with 9 parameters.

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?

Given 9 optional parameters, no annotations, and no output schema, the description is incomplete. It does not say which parameter is required to locate the robots.txt, what a 'group' is, or how errors and edge cases are handled.

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 input schema has 100% description coverage, so the baseline is 3 even without param details in the description. However, the description does not clarify which of the 9 parameters identifies the robots.txt URL, leaving ambiguity between 'url' and 'host' for the caller.

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 verb ('Fetch'), resource ('public robots.txt'), and result ('return group counts only'). This is clear enough to identify the tool's core purpose, though it does not explicitly differentiate it from sibling tools like web-fetch or fetch-status.

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?

There is no guidance about when to use this tool versus alternatives, and no mention of exclusions or prerequisites. With 26 siblings, an agent is left to infer when 'inspect-robots' is the right choice, which is insufficient.

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