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 retrieves a report and returns 'comprehensive deliverability metrics, provider-specific results, and detailed analysis,' which gives some output context. However, it lacks critical behavioral details such as whether this is a read-only operation, authentication requirements, rate limits, error handling, or pagination. For a tool with 7 parameters and no annotations, this is insufficient.

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 moderately concise but includes unnecessary elements. The first part ('- placement test [Get report by cart order id](https://docs.zapmail.ai/get-report-by-cart-order-id-25779763e0.md)') is cluttered with a markdown link that doesn't add clarity. The core sentence is clear, but the overall structure could be improved by removing the link and focusing on the tool's function.

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 tool's complexity (7 parameters, no annotations, no output schema), the description is incomplete. It lacks guidance on usage, behavioral traits, and output details beyond a high-level summary. Without annotations or an output schema, the description should provide more context on what the tool does, how to use it, and what to expect, which it fails to do adequately.

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%, so the schema fully documents all 7 parameters. The description does not add any parameter-specific information beyond implying a cart order ID is needed (not explicitly stated as a parameter). Since the schema handles parameter documentation adequately, the baseline score of 3 is appropriate, with no extra value from the description.

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: 'Retrieve a detailed placement test report for a specific cart order.' It specifies the verb ('Retrieve') and resource ('placement test report'), and distinguishes it from sibling tools by focusing on cart-order-specific reports. However, it doesn't explicitly differentiate from similar tools like 'get_overall_report_25778661e0' or 'get_available_placement_test_credits_25779804e0', which slightly reduces clarity.

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 minimal guidance on when to use this tool. It mentions retrieving a report 'for a specific cart order' but doesn't specify prerequisites (e.g., needing a cart order ID), when not to use it (e.g., for general reports), or alternatives among siblings. The link to another tool is not contextualized as an alternative, leaving usage unclear.

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