List Segments

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 only states 'List contact segments' without mentioning whether the operation is purely read-only, what the response contains, any pagination or ordering, or potential side effects. The verb 'list' implies a safe read, but no explicit behavioral details are given.

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, concise sentence that is front-loaded and contains no filler. Every word adds value for a zero-parameter tool, making it appropriately sized and well-structured.

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?

The tool is simple with zero parameters, but since there is no output schema, the description should ideally convey what the response looks like (e.g., a list of segments with names/IDs) or any relevant behavior like pagination. It does not go beyond the basic action, leaving some gaps in expectations for an agent.

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 tool has zero parameters, and the schema coverage is 100%, so the description is not required to explain parameter details. The baseline of 4 for a zero-param tool is appropriate; the description adds nothing about parameters because there are none to describe.

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 'List contact segments' uses a clear verb (List) and a specific resource (contact segments), which distinguishes it from general 'segments' and implies a collection action versus a single-segment operation like reach_segments_get. However, it does not explicitly differentiate from related sibling tools or specify any filtering scope.

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?

There is no guidance on when to use this tool versus alternatives such as reach_segments_get or reach_segments_profile_contacts. The description simply states the action without any context, exclusions, or mention of alternative tools for specific use cases.

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