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

Goes well beyond the annotations: discloses ~40 requests, 25 s and 8 MB ceilings, the 422-for-private/malformed-address behaviour (and that it isn't charged), the fact a failing part is reported with its error rather than a failed call, pricing (USD 0.01, no free tier), and a prompt-injection warning about returned page text. This is unusually rich operational context for an openWorld read tool.

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 purpose, then routing alternatives, then operational limits, so the important material comes first. It is dense and comma-spliced into long sentences, but nearly every clause carries distinct information; only the enumeration of scored items is slightly over-packed.

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?

An output schema exists, so return values needn't be explained, and the annotations already cover the read-only/idempotent safety profile. What remains for the agent to know — cost, latency, failure semantics, address restrictions, injection caution — is all present, leaving no practical gap.

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 coverage is 100% and the schema already documents the URL constraint. The description adds only marginal semantics, but the origin-only behaviour ('only its origin is used, so https://example.com/docs checks https://example.com') is genuinely useful and not obvious from the schema maxLength/minLength constraints alone.

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 and resource ('Returns 0-100 scores') and enumerates exactly what is scored: llms.txt, robots rules, sitemap, schema.org, OpenAPI, /.well-known, MCP, auth-free access and pay-per-call. It explicitly distinguishes itself from siblings check_robots_txt, check_mcp_server and generate_agent_ready_files, so an agent can place it 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?

Gives explicit alternatives and the condition that selects each: check_robots_txt for one URL's robots rule, check_mcp_server for a live MCP probe, generate_agent_ready_files to fix. It also states scope limits (one pass, https port 443, public addresses), which tells the agent when this tool is not applicable.

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