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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds meaningful behavior beyond that: the tool follows outbound links and validates that they still lead somewhere, which is a nontrivial fan-out not implied by openWorldHint alone. It omits rate limits, timeouts, and result shape.

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, no padding. The functional description is front-loaded and the usage trigger follows immediately; every clause earns its place.

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 one-parameter read-only checker with no output schema, the description conveys what is inspected and the gist of the result (whether links still resolve), which is enough for correct invocation. It could say more about what a failure/report looks like, but nothing critical 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?

Single parameter with 100% schema description coverage ('A public site address'), so the schema already carries the semantics. The description adds no format, protocol, or domain-level detail beyond what the schema provides; 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?

States a specific verb (reads, follows links) and resource (a site's llms.txt), and explains the scope of the check: validating whether the linked pages still resolve. An agent can distinguish this from broad siblings like audit_site or compare_sites 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 an explicit trigger: 'Use it when someone asks about llms.txt or whether their map for AI assistants works.' It does not name a when-not condition or a sibling alternative (e.g., vs audit_site), so it stops short of full routing guidance.

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