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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, and the description still adds real behavior: the operation costs up to 5 fetches and performs an extra edge probe per AI search crawler. It does not mention caching or how repeated calls are deduplicated, but the load/network profile is disclosed, which is exactly the kind of context annotations cannot carry.

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?

Front-loaded with the core action and resource, then layered with the secondary probe behavior and the fetch cost. The closing pointer to the equivalent web tool is somewhat promotional but cheap and useful for parity checks; overall three sentences carry almost no filler.

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 has to describe the return shape, and it does: per-crawler allowed/blocked status with the deciding group and rule named. Combined with the one fully documented input and the cost disclosure, an agent has everything needed to invoke correctly and interpret results.

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?

There is a single parameter with 100% schema description coverage, so the schema already explains that it accepts an absolute http(s) URL or a bare hostname (https assumed). The description adds no further parameter meaning beyond that, so the baseline of 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 states a specific verb and resource (check robots.txt for the 13 tracked AI crawlers) and pins down the exact reporting granularity: per-crawler allow/block plus the deciding group and rule. It also adds a second capability (edge probing as OAI-SearchBot, Claude-SearchBot, PerplexityBot), which clearly distinguishes it from the generic robots/URL siblings without needing to name them.

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?

Usage is implied rather than stated: an agent can infer this is the tool for AI-crawler access questions, and the cost note ('up to 5 fetches') helps with selecting a lighter sibling. But there is no explicit when-to-use guidance, no exclusions, and no pointer to stillindexed_check_robots or stillindexed_check_url for the non-AI case.

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