manage_segments

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

With no annotations provided, the description carries full burden and does well: 'read-only' clearly indicates non-destructive behavior, and 'segments are created in the Kit UI' explains the creation constraint. It doesn't mention rate limits, authentication needs, or response format, but provides essential behavioral context for a read 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 perfectly concise: three short phrases that each add value. 'List Kit subscriber segments' states the core purpose, '(read-only — segments are created in the Kit UI)' provides crucial behavioral context, and 'Actions: list' reinforces the operation. 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 zero-parameter read tool with no annotations and no output schema, the description is adequate but has gaps. It explains what the tool does and its read-only nature, but doesn't describe what the output looks like (list format, fields returned) or any error conditions. Given the simplicity, it's minimally viable.

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 0 parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and instead focuses on the tool's purpose and constraints.

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 tool's purpose: 'List Kit subscriber segments' specifies both the verb (list) and resource (subscriber segments). It distinguishes itself from siblings like 'manage_subscribers' or 'manage_tags' by focusing specifically on segments. However, it doesn't explicitly differentiate from all siblings, just implies 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?

The description provides some usage context: 'segments are created in the Kit UI' implies this tool is for viewing only, not creation. It mentions 'Actions: list' which clarifies the available operation. However, it doesn't explicitly state when to use this versus alternatives like 'manage_subscribers' for subscriber-level operations.

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