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

Annotations already mark readOnlyHint=true and destructiveHint=false, but the description goes well beyond them by disclosing empty-list semantics ('not an error'), the meaning of PENDING/FAILED/READY statuses, that segments are shared with the SaaS UI, and that existing segments remain usable regardless of subscription state. This gives the agent accurate expectations about behavior and non-error outcomes.

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 front-loaded with purpose, then flows naturally into usage, parameter semantics, status meanings, and next-step tool references. It is dense but every sentence earns its place; the STATUS and NEXT sections are clearly delineated, making the text scannable and efficient for an agent.

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?

Even though there is no output schema, the description enumerates the return shape ({id, name, status, last_update_date}) and interprets all status values. It also covers the empty-result case, the fuzzy filter behavior, and the correct downstream calls, so an agent has everything needed to invoke the tool correctly and act on the results.

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% for both optional parameters, so the baseline is 3. The description adds meaningful specificity for the name parameter by defining fuzzy as 'case-insensitive contains or a close match', which goes beyond the schema's terse 'Optional fuzzy search by name'. The sort parameter is already fully described by the schema, so no further description is needed there.

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 opening sentence states a specific verb plus resource: 'List the account's saved Insights (Spotlight) account-journey segments' and enumerates the exact fields returned. It also positions the tool against siblings by explicitly naming create_segment and the downstream NEXT tools, so an agent can distinguish it without opening other definitions.

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 gives explicit when-to-use guidance: 'check here BEFORE create_segment and reuse instead of creating a near duplicate', and explains that an empty result means no segments exist, prompting creation via create_segment when needed. It also lays out the subscribe-state precondition for creating segments and recommends relaying refusal to the user, making the decision boundary between list_segments and create_segment unambiguous.

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