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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering safety and side-effect profile. The description adds value by stating the output contains IDs, metadata, settings, and sync configuration, and uses 'bounded' to imply result limits. No contradiction with annotations; adds contextual detail beyond what annotations provide.

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?

Two sentences with no wasted words. The first sentence front-loads the primary action and scope ('Return bounded Segment warehouse connections'), followed by the included fields and a brief purpose statement. Efficient 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?

For a list tool with three well-documented parameters and safety annotations covering side effects, the description provides sufficient context about the resource and output fields. It does not explicitly explain pagination behavior, but the cursor parameter is documented in the schema and the term 'bounded' hints at limits. Given the absence of an output schema, the description gives a reasonable outline of return contents, though it could be slightly more explicit about the response structure.

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 has 100% description coverage for all three parameters (limit, cursor, _apiKey), each with clear descriptions. The tool description does not add any additional parameter semantics beyond the schema, so it meets the baseline of 3 but does not exceed it. It doesn't clarify parameter interactions or formatting beyond what schema already states.

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 states a specific verb 'Return' with a specific resource 'Segment warehouse connections' and lists the included fields (IDs, metadata, settings, sync configuration). It also clarifies the purpose ('Answers which analytical warehouses receive unified customer data'), clearly distinguishing it from sibling tools like segment_list_destinations and segment_list_sources which target other resources.

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 about what the tool does (listing warehouses) but does not explicitly mention when to use it versus alternatives. However, the resource name 'warehouses' and the sibling tool names make the differentiation implicit, so an agent can infer usage without confusion. Lacks explicit 'use instead of' guidance, hence not a 5.

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