Zapmail MCP Server

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It mentions checking 'availability and pricing' but doesn't disclose rate limits, authentication requirements, response format, error conditions, or whether this is a read-only operation. For a batch operation with potential cost implications, this is inadequate disclosure.

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 communicates the core functionality without wasted words. It's appropriately sized for a straightforward batch checking tool and front-loads the essential information.

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 batch domain checking tool with no annotations and no output schema, the description is insufficient. It doesn't explain what information is returned (availability status, pricing details, error handling for invalid domains), nor does it address behavioral aspects like rate limits or authentication. The context signals indicate moderate complexity (2 parameters), but the description fails to provide necessary operational context.

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 fully documents both parameters ('domains' array and 'years' number). The description adds no additional parameter context beyond implying batch processing through 'multiple domains at once.' No syntax, format, or constraint details are provided beyond what's in the schema.

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 ('Check availability and pricing') and resource ('multiple domains at once'), making the purpose immediately understandable. It distinguishes from the sibling 'check_domain_availability' by specifying batch capability, though it doesn't explicitly contrast with other domain-related tools like 'purchase_domains' or 'get_available_domains'.

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 doesn't mention prerequisites, appropriate contexts, or compare with similar tools like 'check_domain_availability' (single domain) or 'purchase_domains' (buying domains). The agent must infer usage from the name and description alone.

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