Preview campaign recipients before sending to review total count and sample list.
Preview the recipient set for a campaign before sending. Returns count + sample list.
| Name | Required | Description | Default |
|---|---|---|---|
| apiKey | No | Send16 API key (overrides SEND16_API_KEY env var) | |
| campaignId | Yes | Campaign ID |
Changes observed during successful MCP inspections.
v0.5.7Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden. It states the tool returns a count and sample list, implying a read-only operation, but does not disclose any side effects, limitations (e.g., sample size), or error conditions. This is adequate but minimal.
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 sentence that conveys core functionality efficiently. It is appropriately sized given the tool's simplicity, with no unnecessary words. Slight deduction for missing details that could be added concisely.
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?
Without an output schema, the description should clarify the return format. 'Count + sample list' is helpful but underspecified (e.g., sample size limit, pagination). Error behavior and prerequisites are absent, making it somewhat incomplete for a preview tool.
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 baseline is 3. The description adds no additional meaning beyond the schema definitions. It does not explain parameter usage context or relationships.
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 verb 'Preview' and the resource 'recipient set for a campaign', which distinguishes it from sibling tools like 'preview_segment' that target segments instead of campaigns. It is specific and actionable.
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 implies usage 'before sending' but does not explicitly state when to use or avoid this tool, nor does it mention alternatives among siblings. The context is clear but lacks exclusionary guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.