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 'local rules' but doesn't explain what these rules entail (e.g., formatting constraints, language restrictions, or business logic). It also fails to disclose behavioral aspects like whether the tool is read-only, has rate limits, or what the output format might be, which is inadequate for a tool with no 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 a single, efficient sentence with no wasted words. It is front-loaded with the core action and resource, making it easy to parse quickly, which is ideal for conciseness.

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 (4 parameters, no annotations, no output schema), the description is incomplete. It lacks details on behavioral traits, output expectations, and usage context. For a tool that generates domain suggestions, more information on result format or constraints would be necessary for effective agent 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 input schema has 100% description coverage, so the schema fully documents all four parameters. The description adds no additional meaning beyond the schema, such as explaining how keywords are processed or what 'local rules' imply for parameter usage. This meets the baseline score of 3 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 states the tool 'Generate professional domain name suggestions (local rules)' which specifies the verb ('Generate'), resource ('domain name suggestions'), and a qualifier ('professional', 'local rules'). However, it doesn't clearly differentiate from sibling tools like 'generate_name_pairs' or 'generate_usernames' that also generate names, making the purpose somewhat vague in context.

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 any prerequisites, exclusions, or compare it to other domain-related tools in the sibling list (e.g., 'check_domain_availability', 'purchase_domains'), leaving the agent without context for tool selection.

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