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 effectively communicates that this is a read-only operation ('Get') with local-only execution ('no remote calls'), which covers basic safety and scope. However, it doesn't disclose potential side effects, performance characteristics, authentication requirements, or rate limits, leaving some behavioral aspects unspecified for a tool that interacts with a sync service.

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 a single, well-structured sentence that efficiently communicates purpose, scope, included metrics, and key behavioral constraint ('no remote calls'). Every element earns its place with zero wasted words, making it immediately understandable without requiring parsing of unnecessary details.

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 tool's zero-parameter simplicity and lack of annotations/output schema, the description provides adequate coverage of what the tool does and its local scope. However, for a tool that presumably returns structured statistics data, the absence of any output information (format, example values, or interpretation guidance) represents a notable gap, especially since there's no output schema to compensate.

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 zero parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and instead focuses on what the tool returns (connection pool statistics), which adds value beyond the empty input 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 clearly states the specific action ('Get'), resource ('IMAP connection pool statistics'), and scope ('from the local sync service'), with additional clarifying details about what's included ('connection reuse rate and active connections') and what's excluded ('no remote calls'). It effectively distinguishes this tool from siblings like get_sync_health or check_connection by focusing on local pool metrics rather than remote connectivity or overall sync status.

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 it retrieves local connection pool statistics, which implies usage for monitoring internal sync service performance. However, it doesn't explicitly state when not to use it or name specific alternatives among the sibling tools, though the focus on 'local' vs 'remote' helps differentiate from tools like check_connection.

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