Create Segment

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

With no annotations provided, the description bears the full burden of behavioral disclosure. It only states 'Create a new contact segment' without revealing any behavioral traits such as whether it's a mutating operation, required permissions, idempotency, or what happens to existing data. This lack of detail is a significant gap for a create operation.

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 directly states the tool's purpose with no redundant or irrelevant content. It is appropriately sized for a simple create operation and is 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?

Given the lack of annotations and output schema, the description is too sparse to be complete. It doesn't explain the expected behavior of the 'conditions' parameter, the response format, or any constraints on the segment name. For a create tool, this leaves the agent without enough context to use it correctly beyond the most basic level.

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 input schema provides descriptions for both parameters (name and conditions), achieving 100% schema description coverage. The description adds no extra meaning beyond the schema, so the baseline of 3 is appropriate. 'conditions' lacks a type in the schema, but the description doesn't compensate for that.

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 the action ('Create') and the resource ('a new contact segment'), which is specific and distinguishable from the sibling list/get tools. However, it doesn't explicitly differentiate from similar create tools like reach_contacts_create, and the term 'segment' could be confused with 'group' from reach_contacts_groups, so it's clear but not fully differentiating.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, the relationship to reach_segments_list/get, or when a segment would be appropriate compared to other contact grouping methods. There is no implied usage context beyond the name.

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