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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds substantial behavioral context: it explains the meaning of the `continues_from_segment` field (continuation vs. fresh shot), the pagination behavior (limit/offset, 0 returns all), and that each segment's assets include overlays. It also discloses the return shape {total, offset, returned, segments}. No contradictions with annotations.

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 longer than typical but every sentence contributes: it covers the return shape, pagination, the continuation semantics, and the overlay auditing capability. It is front-loaded with the core purpose, and the subsequent paragraphs expand on important behavioral details without redundancy. It earns its length given the tool's complexity.

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 read-only listing tool with three parameters, no output schema, and rich annotations, the description covers everything an agent needs: the return structure, the pagination pattern, the special meaning of a field, and how the result relates to other tools. The description is complete enough to call the tool correctly without additional context.

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 parameters are already described. The description goes beyond the schema by explaining the pagination intent ('page through with offset/limit rather than fetching all segments') and clarifying that segment_number (not a parameter here) is the handle for other tools. It reinforces the meaning of limit/offset without repeating the schema text verbatim, adding contextual value.

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 opens with a specific verb ('List') and resource ('storyboard's segments'), then enumerates the returned fields (narration span, type, duration, creative direction). It explicitly states that segment_number is the handle used by all segment tools, and distinguishes itself from sibling tools like get_segment_assets by noting it is the one call that audits every overlay. This clearly separates it from the get_segment_assets sibling.

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 guidance on when to use this tool: to list segments and to audit overlays, and it tells the agent to page through large projects with offset/limit rather than fetching everything. It also points to set_segment_continuation for adjusting the continuation field, giving an alternative action. No ambiguity about when to use it versus other list tools.

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