mailkite_suggest_subdomain

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

Annotations already indicate readOnlyHint=true, so the description's read-only note is redundant, but it adds useful context: the suggestion does not reserve the name, and it requires a management session token. This goes beyond annotations and clarifies side effects.

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 concise, front-loaded with the primary purpose and the critical read-only caveat early. Every sentence adds value, and the guidance about not hard-coding zones is important and clearly stated.

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 that there is no output schema, the description covers the essential behavioral and return contract adequately, but it could potentially mention the format of the returned label or any additional response contextheb. However, for a suggestion tool with zero parameters, it is nearly complete.

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 has no parameters, so the schema provides no semantics. The description explains the return contract (subdomain label and the base zone) and emphasizes the importance of using the returned zone, which is critical for correct invocation.

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 clearly states that the tool suggests a free, unclaimed subdomain label, and it specifies it is read-only and does not reserve the name. This is distinct from potential siblings like claim_subdomain or check_subdomain, though it does not explicitly name alternatives.

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 provides strong guidance on when to use (to prefill input) and explicitly instructs not to hard-code the zone, but does not explicitly say when not to use it or name alternatives. The guidance on taking the zone from 'base' is practical and actionable.

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