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 states the tool is for searching, implying a read-only operation, but does not specify if it requires authentication, has rate limits, returns paginated results, or what the output format might be. For a search tool with 7 parameters and no annotations, this lack of detail is a significant gap in transparency.

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 function without unnecessary words. It is front-loaded with the core action ('Search for mailboxes') and briefly lists key criteria, making it easy to understand at a glance. Every part of the sentence contributes to clarifying the tool's purpose.

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 does not explain behavioral aspects like authentication needs, rate limits, or result formatting. While the schema covers parameters well, the description fails to provide necessary context for safe and effective use, especially for a search operation that might involve sensitive data or large datasets.

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 description mentions criteria like 'name, username, domain, or status,' which loosely maps to parameters such as firstName/lastName, username, domain, and status. However, with 100% schema description coverage, the input schema already fully documents all 7 parameters, including enums for status and serviceProvider. The description adds minimal value beyond the schema, so it meets the baseline score of 3.

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: 'Search for mailboxes using various criteria.' It specifies the verb ('Search') and resource ('mailboxes'), and mentions the types of criteria (name, username, domain, status). However, it does not explicitly differentiate from sibling tools like 'retrieve_all_mailboxes_13490172e0' or 'domain_with_filter_10125073d0', which might offer similar filtering capabilities, so it misses the top 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 does not mention prerequisites, exclusions, or compare it to sibling tools such as 'retrieve_all_mailboxes_13490172e0' (which might retrieve all mailboxes without filtering) or 'bulk_update_mailboxes' (which might modify mailboxes). Without such context, users must infer usage from the tool name and parameters alone.

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