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 states the tool tests connections using stored credentials, implying a read-only diagnostic operation, but lacks details on permissions needed, rate limits, whether it's destructive, or what the output format might be. For a tool with zero annotation coverage, this is insufficient to fully inform the agent.

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, efficient sentence that directly states the tool's purpose without any redundant or unnecessary information. It is front-loaded and appropriately sized for a zero-parameter tool, 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 the complexity of testing email server connections, the lack of annotations, and no output schema, the description is incomplete. It doesn't explain what the test entails, what results to expect (e.g., success/failure status, error details), or behavioral aspects like timeouts or side effects. This leaves significant gaps for the agent to understand the tool's full 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?

The tool has 0 parameters, and schema description coverage is 100%, so there are no parameters to document. The description doesn't need to add parameter semantics, and it appropriately doesn't mention any. A baseline score of 4 is given as it handles the lack of parameters correctly without introducing confusion.

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 action ('Test email server connections') and the resource ('IMAP and SMTP for all configured accounts'), making the purpose specific and understandable. However, it doesn't explicitly differentiate from sibling tools like 'get_sync_health' or 'get_connection_pool_stats', which might also involve connection-related checks, so it doesn't reach the highest score.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., stored credentials must be set up), exclusions, or compare it to siblings like 'get_sync_health' for health checks or 'list_accounts' for account status. This leaves the agent with minimal context for tool selection.

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