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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds real behavioral context beyond that: it discloses the return contents (per-crawler allow/disallow, matching group and rule, sitemaps, Content-Signal lines, warnings) and flags directory crawlers that may ignore robots.txt for user-initiated fetches.

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?

Four dense sentences, front-loaded with scope before inputs and outputs, and nothing is wasted. The trailing 'Same as GET https://bozos.si/api/v1/robots-check' is slightly redundant noise for an agent already holding the tool definition.

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?

With no output schema, the description carries the return-value burden and does so explicitly, and it clarifies the no-fetch input model and the RFC basis. Annotations handle safety, so nothing material is missing for correct invocation.

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%, so the schema already documents path, agent, and robots including defaults ('default /', 'every crawler in the directory'). The description only restates that the robots text is passed in; it adds no syntax, encoding, or interaction detail 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?

Specific verb (evaluate) plus resource (robots.txt) with explicit scope: one named crawler or every AI crawler in the directory, per RFC 9309. It clearly separates itself from the sibling buildRobotsTxt (which constructs rather than evaluates) and from fetch (which retrieves).

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?

'Pass the robots.txt text; nothing is fetched' tells the agent this tool evaluates supplied text rather than downloading it, which is the key disambiguation against fetch. It does not name an alternative tool or state when not to use it, so it stops short of full routing guidance.

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