Zapmail MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'enables redirection,' implying a write operation, but does not specify required permissions, whether the change is reversible, potential side effects, or rate limits. The description is minimal and fails to provide essential behavioral context for a tool that likely modifies domain settings, which is a significant gap.

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 with two sentences: one states the purpose, and the other is a generic instruction ('Invoke this endpoint'). It is front-loaded with the core functionality. However, the second sentence is redundant and does not add value, slightly reducing efficiency, but overall, it is well-structured and avoids unnecessary verbosity.

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 a tool with 7 parameters, no annotations, and no output schema, the description is incomplete. It lacks details on behavioral aspects (e.g., auth needs, effects), usage context, and does not compensate for the absence of structured fields. For a tool that likely performs a write operation on domains, this minimal description is inadequate to guide an agent 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?

The input schema has 100% description coverage, so the schema already documents all 7 parameters (e.g., 'method', 'path', 'body'). The description does not add any parameter-specific details beyond what the schema provides, such as explaining how 'method' or 'path' relate to domain forwarding. With high schema coverage, the baseline score of 3 is appropriate, as the description adds no extra semantic value.

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: 'Enables redirection from one or more registered domains to a specified destination domain.' It specifies the verb ('enables redirection') and resource ('registered domains'), making it understandable. However, it does not explicitly differentiate from sibling tools like 'enable_email_forwarding_13521023e0' or 'connect_domain_with_zapmail_13521006e0', which might involve similar domain-related actions, so it lacks sibling differentiation.

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 does not mention prerequisites (e.g., needing registered domains), exclusions, or compare it to siblings such as 'enable_email_forwarding_13521023e0'. The phrase 'Invoke this endpoint' is generic and does not add contextual usage information, leaving the agent without clear direction.

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