MCP Email Service

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the destructive action ('delete', 'move to trash', 'permanently delete') and routing requirements, but lacks details on permissions needed, error handling, rate limits, or what happens if emails are already deleted. For a destructive tool, this is insufficient.

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 appropriately sized with two sentences that are front-loaded with the core purpose. The first sentence states the action, and the second provides critical routing information, with no wasted 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?

For a destructive tool with 7 parameters, no annotations, and no output schema, the description is incomplete. It lacks information on return values, error conditions, side effects, or prerequisites beyond routing. The agent would struggle to use this tool safely and effectively without additional context.

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 schema fully documents all 7 parameters. The description adds minimal value beyond the schema by hinting at the account routing logic ('Provide account_id or email_accounts mapping'), but doesn't explain parameter interactions or semantics not covered in the schema descriptions.

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 the tool's purpose with specific verbs ('delete', 'move to trash', 'permanently delete') and resources ('emails'), distinguishing it from siblings like 'delete_email' (singular) and 'batch_delete_emails' by specifying it handles one or more emails with routing logic.

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 description provides clear context about when to use this tool by specifying the need for account routing ('Provide account_id or email_accounts mapping'), but it doesn't explicitly mention when not to use it or name alternatives like 'delete_email' for single emails or 'batch_delete_emails' for bulk operations without routing.

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