Retrieve a contact list and its contact count by UUID to inspect list details and size for audience management.
Get a contact list with its contact count.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Contact list UUID |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full burden. It implies a read-only operation and mentions the contact count, but does not disclose error behavior, permissions, or what happens if the id is invalid.
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?
One short sentence, front-loaded with the core action, and no wasted words.
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 get-by-id tool with no output schema, the description is too sparse. It only mentions contact count and omits any details about the returned list fields (e.g., name, created date) or error handling, leaving the agent with insufficient context to interpret the response.
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 coverage is 100% and the single 'id' parameter is fully described in the schema. The description adds no additional meaning beyond what the schema provides, so the baseline 3 is appropriate.
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 (Get) and resource (contact list) and adds that it returns the contact count. It is clear it retrieves a single contact list, distinct from list_contact_lists, though it doesn't explicitly say 'by id'.
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?
Provides no explicit guidance on when to use this tool versus list_contact_lists or other CRUD siblings. The only implied usage is retrieving a single list if you have its id, but alternatives and conditions are not mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.