Zapmail MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool 'allocates domains' and 'enables DNS Shield protection,' implying a write/mutation operation, but lacks details on permissions, side effects (e.g., billing implications), rate limits, or error handling. The description is too vague for a tool that likely modifies subscription state, leaving significant behavioral 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?

The description is concise and front-loaded, with two sentences that directly state the tool's purpose and action. There's no unnecessary fluff, and each sentence contributes to understanding the tool's function. However, the final sentence 'Invoke this endpoint' is redundant and adds no value, slightly detracting from perfect efficiency.

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 a domain allocation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what 'DNS Shield protection' entails, how allocation interacts with subscription limits, what the response looks like, or potential errors. For a mutation tool with rich sibling context, more detail is needed to guide 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 input schema has 100% description coverage, so the schema already documents all 7 parameters (e.g., 'method', 'path', 'body'). The description adds no parameter-specific information beyond implying domains need to be allocated, which doesn't clarify how parameters like 'body' or 'query' should be used for this operation. Baseline 3 is appropriate as 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 clearly states the tool's purpose: 'Allocate domains to your DNS Shield LTD subscription slots and enable DNS Shield protection.' It specifies the verb ('allocate'), resource ('domains'), and outcome ('enable DNS Shield protection'), making the action explicit. However, it doesn't differentiate from sibling tools like 'get_allocated_domains_for_subscription_25781672e0' or 'purchase_dns_shield_25782088e0', which prevents a perfect score.

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 mentions 'available LTD plan capacity' but doesn't clarify prerequisites, such as needing a subscription or available slots, nor does it reference sibling tools like 'get_available_slots_25781438e0' or 'get_eligible_domains_25781361e0' for context. The phrase 'Invoke this endpoint' is generic and adds no usage context.

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