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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses non-obvious behavioral details: it filters to verdict changes, includes sitemap additions, and tracks whether parse errors went up or down. This goes well beyond what annotations provide and helps the agent anticipate the tool's output style.

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?

Two sentences, with the core behavior front-loaded and no redundant wording. The motivating question is answered efficiently without repeating schema data or annotation values.

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 explains what the tool returns: changed crawler verdicts, sitemap additions, and parse-error trends, which is important because no output schema is provided. It stops short of describing the exact response structure, but an agent has enough context to invoke the 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 description coverage is 100%, so before, after, and path are already documented in the input schema. The description adds no parameter-specific detail, but none is needed because the schema carries the full burden; baseline 3 applies.

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 clearly states a specific action: compare two robots.txt versions and report only crawlers whose verdict changes at a given path. It explicitly distinguishes itself from a text diff, making the tool's purpose unambiguous even without inspecting 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?

The description frames the intended use case: checking whether a robots.txt edit did what was meant and did not cause unintended changes. It does not explicitly name sibling alternatives or state when not to use it, but the context is clear enough for an agent to choose it appropriately.

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