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

Annotations already declare readOnlyHint and openWorldHint, and the description adds genuinely useful behavioral context: which access-control source is consulted (robots.txt), which signals drive the score, and that the score is 0-100 with a findings list. It stops short of noting rate limits, caching, or failure behavior on unreachable URLs.

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?

One dense sentence that front-loads the core purpose and then the output shape; the parenthetical crawler/signal lists are long but each item is informative. No filler sentences, though the readability clause slightly crowds the primary crawler-access purpose.

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 correctly carries the return-value burden by naming the 0-100 score and findings list. Combined with a fully documented single parameter, an agent has enough to call it correctly; only failure/timeout behavior is unaddressed.

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 single 'url' parameter is fully documented in the schema (100% coverage), including an example, so the baseline of 3 applies. The description adds only the constraint that the URL must be public, which is marginal 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?

The description states a specific verb and resource (check crawler access for a URL per robots.txt) and enumerates the exact crawlers and readability signals examined. It is clearly distinguishable from siblings like read_url (fetches content) and generate_ai_robots_txt (produces a file).

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 by the name and content but never stated: no 'use this when...' guidance, no conditions for choosing it over read_url or ai_visibility_score. It also gives no prerequisites (e.g., that the page must be publicly reachable).

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