plunk_list_segment_contactsList contacts in a Plunk segment by UUID to verify who a campaign will reach before sending.
Purpose: List the contacts currently in a segment.
Not for: The segment's definition, which is plunk_get_segment.
Returns: The contacts in this segment.
Use when: Checking who a campaign would actually reach before sending to this segment.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Segment UUID |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered by structured data. The description's 'Returns' line merely restates the purpose and adds no pagination, result-size, or auth context, so it contributes little beyond the annotations.
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 labeled-section format is front-loaded and easy to scan, with no wasted preamble. The 'Returns' section is somewhat redundant with 'Purpose', keeping it short of a 5.
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 simple single-parameter read tool with no output schema, the description covers purpose, exclusion, and usage trigger adequately. It omits any note on pagination or result limits, which is the only meaningful gap.
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?
Only one parameter, documented at 100% schema coverage ('Segment UUID'), so the schema already carries the semantics. The description never references the id parameter or its format, leaving it no better than the schema baseline.
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?
States a specific verb and resource ('List the contacts currently in a segment') and explicitly names the sibling it is not (plunk_get_segment for the definition). An agent can distinguish it from all segment-related siblings without opening any schema.
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?
Contains both a 'Not for' exclusion routing to plunk_get_segment and a concrete 'Use when' trigger (checking who a campaign would actually reach before sending). This is explicit when-to-use and when-not-to-use guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.