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

Beyond the annotations (readOnly, openWorld, non-destructive), the description discloses the six probe regions, the four possible per-region outcomes (up, down, blocked, inconclusive), that status codes and timings are returned, that no page content is ever returned, and a 5-minute-per-host cache with the age of a repeated result. That caching note is especially valuable because idempotentHint=false would otherwise leave the repeat-call behavior ambiguous.

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?

The trigger condition is front-loaded, followed by what the call does, then behavioral caveats, then exclusions in descending order of importance. Although longer than one line, every sentence carries decision-relevant information and none restates the tool name or schema.

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 fully compensates by enumerating the returned fields (per-region result, status code, timings, overall verdict). Combined with the rate limit, silent caching, and scope exclusions, an agent has everything needed to call this correctly and to interpret 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?

There is a single parameter and schema coverage is 100%, so the schema already explains the URL format and that query strings are ignored. The description adds only scope (host-level, not path-level) and no format or normalization guidance beyond the schema, which is the baseline for a fully documented 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?

The description states a specific verb and resource — request a URL once from six named regions and return per-region status plus an overall verdict. It explicitly separates itself from check_service_status (named third-party vendors) and diagnose_site (FlareWarden-monitored sites), so an agent can route correctly without opening any 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?

It opens with an explicit trigger ('when the user asks whether a specific website, URL or API endpoint is down, unreachable or slow') and gives verbatim user phrasings. It also names two exclusions with the exact alternative tool for each, so both when-to-use and when-not-to-use are covered.

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