Better Email MCP

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

Annotations cover basic hints (readOnlyHint: false, destructiveHint: false, etc.), so the description adds value by detailing specific actions and query syntax. However, it doesn't disclose additional behavioral traits like rate limits, authentication needs, or error handling beyond what annotations provide.

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 and front-loaded with key actions, though it could be more structured (e.g., separating action types). Every sentence adds value, but minor improvements in organization could enhance clarity.

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 the complexity of 8 parameters, no output schema, and annotations covering basic hints, the description is adequate but incomplete. It lacks details on return values, error cases, or prerequisites, leaving gaps for an AI agent to fully understand tool behavior.

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 parameters. The description adds minimal semantics by listing actions and query examples, but doesn't provide significant meaning beyond what's in the schema, aligning with the baseline for high coverage.

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 handles email messages with specific actions (search, read, mark_read, etc.), which is a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'attachments' or 'folders', though the domain focus is clear.

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 implies usage through action enumeration and query examples, but doesn't provide explicit guidance on when to use this tool versus alternatives like 'send' or 'attachments'. It mentions filtering by account, which offers some context, but lacks clear when/when-not directives.

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