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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe outbound read. The description adds that results report 'what is missing,' but says nothing about failure behavior for unreachable sites, timeouts, or how many requests are made—useful context for an open-world fetch.

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?

A single sentence that front-loads the action and enumerates the checked artifacts with zero filler. Every clause carries information.

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?

There is no output schema, so the description bears responsibility for describing the return value; it only gestures at it ('what is missing') without stating the shape of the result (per-artifact found/missing status). Adequate to call, but not complete for interpreting the response.

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?

Only one required parameter and schema description coverage is 0%, but 'business website' makes the intent of url fairly evident. It does not specify format expectations (scheme, trailing path), so it adds little beyond the schema; baseline 3 for an obvious single parameter.

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 ('Check whether') and a specific resource (a business website), plus enumerates the exact artifacts being probed (llms.txt, agent.json, OpenAPI, A2A agent card). None of the sibling tools overlap with this capability, so an agent can select it unambiguously.

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 only implied by the purpose sentence; there is no explicit 'use this before calling X' or 'use when you need to qualify a provider' guidance. It also omits prerequisites such as whether the URL must include a scheme or be a root domain.

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