reach_listProfileSegmentsV1

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 adds valuable context: 'the number of contacts currently matching it, which is recalculated on read rather than stored,' and explains the count_type parameter's behavior. This goes beyond what the schema states, though it does not detail other aspects like error handling or response structure.

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 covering purpose and key behavioral nuances. There is no redundancy or extraneous information. Every sentence earns its place, making it easy for an agent to parse and act upon.

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 paginated list tool with fully described parameters, the description covers the essential aspects: what it returns (a list of segments with contact counts), the pagination aspect, and the non-obvious count behavior. It does not explicitly describe the response format beyond the count, but this is sufficient given the tool's simplicity. The lack of an output schema is mitigated by the clear description of the entries.

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 baseline is 3. The description adds meaning by elaborating on count_type: 'Use count_type to count either every matching contact or only the subscribed ones,' which clarifies the enum values beyond their schema descriptions. The other parameters (page, per_page, profileUuid) are adequately described in the schema and do not need further explanation.

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: 'Get a paginated list of the segments defined in a profile.' This specifies the verb (Get), the resource (segments), and the scope (defined in a profile), distinguishing it from sibling tools like reach_listSegmentsV1 that may not be profile-scoped.

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 clear context: use this tool to retrieve segments belonging to a specific profile. It does not explicitly name alternatives or exclusions, but the profile-scoped wording implicitly differentiates it from broader segment list tools. This is sufficient for an agent to decide when to invoke it.

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