Zapmail MCP Server

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 fetching 'authenticated user' details, implying it requires authentication, but doesn't specify required permissions, rate limits, or error handling. The description lacks details on response format, pagination, or side effects, which is inadequate for a tool with 7 parameters and no output schema.

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 concise and front-loaded, stating the core purpose in the first sentence. The second sentence ('Invoke this endpoint.') is redundant and adds no value, slightly reducing efficiency. Overall, it's well-structured but could be trimmed for optimal 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 tool's complexity (7 parameters, no annotations, no output schema), the description is incomplete. It lacks details on authentication requirements, response format, error conditions, and how parameters like 'method' or 'path' interact with the tool's stated purpose. This leaves significant gaps for an agent to understand and use the tool effectively.

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 no parameter-specific information beyond implying the tool fetches user details, which doesn't clarify the purpose of parameters like 'method', 'path', or 'workspaceKey'. The baseline score of 3 reflects that the schema does the heavy lifting, but the description fails to add meaningful context.

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: 'fetch details of the authenticated user, including their active plan, mailbox usage, and wallet balance.' It specifies the verb ('fetch'), resource ('authenticated user'), and key data fields. However, it doesn't differentiate from potential sibling tools like 'get_wallet_balance_13490707e0' or 'retrieve_all_workspaces_13489896e0', which might overlap in scope.

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 simply says 'Use this endpoint to fetch details...' without mentioning prerequisites, context, or comparisons to sibling tools like 'get_wallet_balance_13490707e0' for specific data. This leaves the agent with insufficient context for optimal tool selection.

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