MCP Email Service

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

No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: the action (delete), options (move to trash or permanent deletion), and a recommendation for account_id. However, it misses details like permissions needed, error handling, or confirmation prompts, leaving gaps for a mutation tool.

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 front-loaded with the core action in the first clause and efficiently adds crucial details in a second clause. Every sentence earns its place with zero waste, 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?

Given no annotations and no output schema, the description is incomplete for a mutation tool. It covers the basic action and key parameter guidance but lacks details on behavioral outcomes, error cases, or return values, leaving the agent with significant gaps.

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 5 parameters. The description adds minimal value beyond the schema by implying account_id's optionality and recommendation, but doesn't explain parameter interactions or semantics further. Baseline 3 is appropriate as the schema does the heavy lifting.

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 verb ('delete') and resource ('a single email'), specifying it can move to trash or permanently delete. It distinguishes from sibling tools like 'batch_delete_emails' by emphasizing 'single' and from 'delete_emails' (plural) by its singular focus.

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 with 'account_id optional but recommended,' guiding when to include this parameter. However, it lacks explicit alternatives (e.g., when to use 'batch_delete_emails' vs. this tool) or exclusions, which prevents a perfect score.

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