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

Annotations already declare read-only and idempotent behavior, so the bar for extra disclosure is lower. The description adds that it returns a plain text report and checks the 'latest' availability result, providing useful behavioral context beyond the annotations. It does not contradict 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 exactly two sentences, front-loaded with the primary action, and contains no filler or repetition. Every word adds value, making it highly concise and well-structured.

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, read-only tool with no output schema, the description is largely sufficient: it states what is checked and the return format. It does not mention error conditions or what happens if no result is available, but these are minor omissions for such a simple operation.

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 are zero parameters, so the baseline is 4. The description still adds semantic context around the result ('latest availability result'), even though there is nothing to explain about parameters themselves.

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 uses a specific verb ('Check') and resource ('the latest availability result for the built-in Cealing Host'), clearly distinguishing this from sibling tools like generate_host or search_host. It identifies exactly what the tool does and what it reports.

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?

The usage context is implied: use this to check the availability of the Cealing Host. However, no explicit alternatives or when-not-to-use guidance is provided, and sibling tools are not referenced. This leaves the agent to infer when this tool is preferred over search_host or generate_host.

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