Zapmail MCP Server

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

No annotations are provided, so the description must fully disclose behavioral traits. It only mentions 'updating mailbox details' without specifying what details can be updated, permissions required, whether it's destructive, rate limits, or response format. This is inadequate for a mutation tool with zero annotation coverage.

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 two short sentences, but the second sentence ('including: Invoke this endpoint.') is redundant and confusing, adding no value. It's not appropriately structured or front-loaded, wasting space without improving 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 complexity of 7 parameters, no annotations, and no output schema, the description is severely incomplete. It fails to explain what 'mailbox details' entail, how updates are applied, or what the tool returns, making it inadequate for effective use.

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 schema description coverage is 100%, so the schema already documents all 7 parameters thoroughly. The description adds no parameter semantics beyond what's in the schema, such as examples or constraints. Baseline 3 is appropriate when the schema does all the work.

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 'This endpoint allows updating mailbox details, including: Invoke this endpoint.' The first part ('updating mailbox details') provides a basic verb+resource, but the second part ('including: Invoke this endpoint') is nonsensical and adds no clarity. It doesn't distinguish from siblings like 'update_workspace_13489975e0' or 'bulk_update_mailboxes', making it vague and partially tautological.

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?

There is no guidance on when to use this tool versus alternatives. The description offers no context, prerequisites, or exclusions, and it doesn't reference any sibling tools for comparison. This leaves the agent with no usage direction.

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