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

Annotations already declare readOnly, idempotent, openWorld=false, and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: no network fetch occurs, output is one allow/disallow row per token with the vendor stance, and RFC 9309 governs matching.

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?

Three front-loaded sentences with no filler; the core action leads and the anti-fetch constraint follows. The parameter blacklist is slightly long but earns its place by preventing a common wrong invocation.

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 read-only, 3-param tool with no output schema, the description covers the action, the non-fetching behavior, and the return shape (allow/disallow plus vendor stance). Nothing needed to call it correctly is missing.

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 ids, path, and robots_txt are already fully documented in the schema, setting the baseline at 3. The description reinforces the key constraint (robots_txt is contents, not a URL) but adds no syntax or format detail beyond what the schema provides.

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?

States a specific verb (Match) and resource (a pasted robots.txt against Botcard's AI crawler tokens) with a named standard (RFC 9309). It is clearly distinct from siblings like get_crawler and list_crawlers, which retrieve crawler data rather than evaluate a pasted file. An agent can select this without opening the schema.

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?

Explicit negative guidance — 'This tool does not fetch any website. Do not send url, host, target, website, robots_url, or fetch' — steers the agent away from the fetch-style misuse that the sibling tools might model. It gives clear context but does not name an alternative tool by name the way a top-tier definition would.

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