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. It mentions 'update an existing third-party account', implying a mutation operation, but fails to disclose critical behavioral traits such as required permissions, whether changes are reversible, potential side effects, or error handling. For a tool with 7 parameters and no annotations, this 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 brief and front-loaded with the core purpose in the first sentence. However, the second sentence 'Invoke this endpoint' is redundant and adds no value, slightly detracting from efficiency. Overall, it's concise but could be tighter.

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 (7 parameters, no annotations, no output schema), the description is incomplete. It lacks details on behavioral aspects, usage context, and what the update entails, making it inadequate for an agent to understand the tool's full scope and implications in this rich environment.

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%, meaning all parameters are documented in the schema itself (e.g., 'method' overrides HTTP method, 'path' overrides API path). The description adds no additional meaning about parameters beyond implying an update to account details, so it meets the baseline of 3 where the schema does the heavy lifting.

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 'update an existing third-party account used for exporting mailboxes', which provides a verb ('update') and resource ('third-party account'), but it's vague about what specifically gets updated (e.g., credentials, settings). It doesn't distinguish from sibling tools like 'add_third_party_account' or 'add_third_party_account_details_13490752e0', leaving ambiguity about when to add vs. update.

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?

No guidance is provided on when to use this tool versus alternatives. The description only says 'Invoke this endpoint', offering no context about prerequisites, when it's appropriate, or what distinguishes it from related tools like adding accounts. 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.