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

With no annotations, the description must carry behavioral disclosure. It mentions the output (group counts only) but does not disclose that most parameters are discarded or that the tool performs shape checks rather than a single fetch. This is misleading relative to the schema.

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 concise sentence, but it is under-specified and does not earn its place because it omits the tool's actual multi-purpose behavior. It lacks structure or a clear front-loaded summary of what the tool truly does.

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 nine parameters and no output schema, this description is grossly incomplete. It does not explain the parameters, the actual operation, error behavior, or return format, leaving an agent unable to call 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?

The schema provides 100% coverage for parameter descriptions, so the baseline is 3, but the description adds no parameter semantics and actively contradicts the schema by implying a single-purpose robots.txt fetch. This confuses rather than clarifies how the parameters relate to the tool.

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 and resource ('Fetch a public robots.txt and return group counts only'), but the input schema exposes nine unrelated parameters (ref, city, json, zone, etc.) described as shape checks, which contradicts the stated purpose. It does not distinguish itself 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?

No guidance is given on when to use this tool versus alternatives. The description provides no context, prerequisites, or exclusions, leaving an agent to guess the intended use case.

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