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

Annotations already declare read-only, open-world, non-destructive behavior, but the description adds substantial context beyond them: it explains that results combine the vendor status page and FlareWarden regional checks, show the worse verdict, incidents, response times, and 7/30/90-day uptime. This tells the agent what kind of evidence to expect without contradicting the annotations.

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 description is front-loaded with the primary use case, then explains return contents, coverage, and the explicit sibling alternative. Despite being fairly detailed, every sentence adds decision-relevant information and there is no wasted preamble.

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 status check with no output schema, the description supplies the missing context: what data is returned, how the verdict is formed, coverage scope, and when to use the sibling URL tool instead. Nothing needed to call it correctly appears to be 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?

Schema description coverage is 100%, so the single service parameter is already fully documented with name, domain, and status-page URL formats plus examples. The description adds useful scope ('hundreds of popular services') but does not materially expand the parameter semantics beyond the schema.

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: checking whether a named third-party service is down, slow, or having an outage. It explicitly distinguishes this from the URL-specific sibling and gives concrete service examples, so an agent can select it confidently.

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 gives clear when-to-use conditions: user asks whether a third-party service such as Stripe, AWS, GitHub, Slack, OpenAI, or Cloudflare is down or why a dependent system is failing. It also states the exclusion explicitly: 'Not for a specific URL or the user's own website: use check_service_status_url.'

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