list_segment_contacts

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

With no annotations, the description carries the full burden. It adds a meaningful behavioral hint with 'currently resolves to', implying dynamic evaluation rather than a static stored list, and 'Preview'/GET implies read-only. But it does not mention pagination, response shape, or any limits, which are relevant for a list endpoint.

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, front-loaded sentence with no filler. Every word contributes to understanding the tool's scope and behavior.

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-only operation, the description is largely complete. The main gap is the lack of detail about the response format or pagination, but given the simplicity and the absence of an output schema, this is a minor omission.

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 only parameter id is plainly described as 'The segment id.' The description adds no additional meaning beyond the schema, so the baseline of 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?

The description names a specific verb ('Preview') and resource ('contacts a segment currently resolves to'), which clearly distinguishes it from sibling tools like list_segments (lists segments) and list_contacts (lists all contacts). The endpoint reference reinforces the exact operation.

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 purpose itself implies when to use it: to inspect the current contact membership of a particular segment. However, it does not explicitly name alternatives or state when not to use it (e.g., 'use list_contacts for all contacts'), leaving the routing mostly to inference.

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