Check subdomain availability

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

Annotations already explicitly mark as readOnly (readOnlyHint: true) and idempotent (idempotentHint: true). Description adds confirmation of read-only check behavior ('Check whether'). No contradiction.

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?

Single sentence, front-loaded with purpose. No unnecessary words.

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?

Given no output schema and simple input (1 string), description is adequate for a basic check. However, lacks details on return format (boolean vs status) or error conditions, which with simple tools may be acceptable.

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?

Input schema has 0% description coverage for the 'slug' parameter, but the description adds meaning by stating it checks availability, implying 'slug' is the subdomain to check. No additional details on format or constraints beyond 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?

Description clearly states the tool checks subdomain availability with 'Check whether a given subdomain slug is free.' This is specific enough, but doesn't differentiate from sibling 'suggest_subdomain' which might also check availability.

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?

No guidance on when to use this vs alternative tools like 'suggest_subdomain'. No context on prerequisites or typical workflow.

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