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 'add a third-party account' and 'export your mailboxes,' implying a write operation, but fails to detail critical traits such as required permissions, authentication needs, side effects (e.g., data sharing), or error handling. This leaves significant gaps in understanding the tool's behavior and risks.

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 brief (two sentences) but inefficiently structured. The first sentence is vague, and the second ('Supported apps: Invoke this endpoint.') is confusing and adds little value. While not verbose, it lacks front-loaded clarity and wastes space on unhelpful content, making it mediocre in conciseness.

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 fails to explain the purpose in detail, lacks usage context, omits behavioral traits, and provides no insight into return values or errors. This leaves the agent poorly equipped to use the tool effectively in a real-world scenario.

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, documenting all 7 parameters (e.g., 'method' for HTTP override, 'serviceProvider' with enum). The description adds no parameter-specific information beyond what the schema provides, so it meets the baseline of 3 for adequate schema coverage without extra 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 states 'add a third-party account where you want to export your mailboxes,' which provides a vague purpose (adding an account for mailbox export) but lacks specificity about what 'add' entails (e.g., linking, configuring, authenticating). It does not clearly distinguish from siblings like 'update_third_party_account_details_13490787e0' or 'add_billing_details_13490005e0,' making it a tautology that restates the title without meaningful 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 includes 'Supported apps: Invoke this endpoint,' which is unclear and provides no practical guidance on when to use this tool versus alternatives. It does not mention prerequisites, context (e.g., after setting up export), or exclusions, leaving the agent with no actionable usage instructions beyond a generic invocation hint.

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