reach_createAProfileSegmentV1

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explicitly states that membership changes as contacts change and that creating a segment does not modify any contact, which is valuable beyond the basic 'create' action. It doesn't cover every edge but provides solid transparency.

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 extremely concise: two sentences that front-load the action and then add one clarifying concept. No filler or redundant detail.

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 description is conceptually complete for a create operation: it defines the resource, explains its dynamic nature, and reassures that contacts aren't modified. Given the rich parameter schema, only the return value and any permission requirements are left unspecified, which is a minor 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?

Schema coverage is 100%, so the parameters are well-documented in the input schema itself. The description adds general context about conditions but doesn't provide additional parameter-level semantics beyond what the schema already specifies.

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 'Create a segment in a profile', using a specific verb and resource. It further clarifies that a segment is a saved set of conditions rather than a fixed list, which distinguishes it from related tools that create contacts, tags, or static lists.

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 explains the concept of a segment and when you'd conceptually use it (creating a dynamic, condition-based segment). However, it does not explicitly compare with sibling tools like reach_createANewContactSegmentV1 or indicate when NOT to use this tool, so usage guidance remains implied rather than explicit.

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