Delete Mail User

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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the safety profile is covered. The description adds the non-obvious side effect 'Flushes MCP cache,' but does not explain permanence, auth requirements, or cache-flush consequences.

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?

Two compact labeled lines, purpose first and side effect second. There is no filler, and the critical routing information is front-loaded.

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 two-parameter delete operation with rich annotations and full schema coverage, the description supplies the endpoint and a key side effect. It stops short of usage conditions, but the structured fields already carry safety and parameter details, so an agent has enough to call it correctly.

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 coverage is 100% and both required parameters are described there ('User mkey', 'Domain name'). The description only repeats the path placeholders domain and key, adding no syntax or meaning 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 gives the exact HTTP route DELETE /v1/domains/{domain}/users/{key}, and the title identifies the resource as a mail user. That is a specific verb and resource that separates it from sibling users.get/create/update.

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 when-to-use guidance, prerequisites, or alternatives are provided. The endpoint implies deletion, but the description does not say when this tool should be selected over users.update or other user-management siblings.

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