Zapmail MCP Server

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

No annotations are provided, so the description carries full burden. It mentions workspace context dependency but doesn't disclose other behavioral traits like whether this is a read-only operation, what format the output takes, if there's pagination, rate limits, or authentication requirements. For a list operation with zero annotation coverage, this leaves significant gaps.

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?

Two concise sentences that are front-loaded with the core purpose. Every sentence earns its place: the first states what the tool does, the second provides essential context about workspace selection.

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?

For a simple list operation with one optional parameter and no output schema, the description covers the basic purpose and context adequately. However, without annotations or output schema, it should ideally provide more behavioral context about the response format and operational characteristics to be fully complete.

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?

Schema description coverage is 100%, so the schema already fully documents the single optional parameter 'contains'. The description doesn't add any parameter-specific information beyond what's in the schema, which meets the baseline expectation when schema coverage is high.

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 action ('List') and resource ('domains'), and specifies the scope ('in the active workspace'). It doesn't explicitly differentiate from sibling tools like 'retrieve_all_domains' or 'list_assignable_domains', but the workspace context provides some distinction.

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 clear context for when to use this tool ('in the active workspace') and references an alternative action ('Use set_context to choose the workspace') for workspace selection. However, it doesn't explicitly mention when NOT to use it or compare it to similar domain-listing siblings.

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