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

Adds substantial behavior beyond the annotations: the operation is asynchronous, can run up to two minutes, may return a "started" status, and requires polling website_health. It also explains the persistence implied by readOnlyHint=false ("keep the result") and notes there is no cost. These are exactly the non-obvious traits an agent needs to schedule and follow up correctly.

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?

Three short sentences, front-loaded with the action, then cost, then timing and follow-up. Every sentence carries information the agent needs (what, price, duration, next step) with 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?

For a zero-parameter, no-output-schema tool the description covers the async lifecycle and the follow-up call, which is the main risk of misuse. It leaves unstated what the eventual result contains or what to do if the check fails or never completes, a minor gap given there is no output schema to lean on.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless schema applies. No parameter-related noise or misleading hints are present.

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: check the owner's own website "the way a search engine does" and persist the result. It also implicitly positions itself ahead of the sibling website_health, which it names as the follow-up. It stops short of explicitly contrasting with the other check_* siblings, so a 4 rather than a 5.

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 concrete operational guidance: the call is free, it may take up to two minutes, and if the response says "started" the agent should call website_health shortly after. That is a clear use-and-chain instruction. It does not state when not to use it versus siblings like website_health directly, nor any prerequisite about site ownership.

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