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

Annotations already cover readOnly/idempotent/non-destructive, so credit goes to the added behavior: both video and story are null while the video is private, and 'Never its maker's written brief' discloses an important privacy exclusion. These are meaningful traits beyond the 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?

Despite being a single dense run-on sentence, every clause carries relevant information about the returned fields. Readability suffers from the lack of structure, but no fluff is present.

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?

With no output schema, the description usefully enumerates the returned video and story fields, compensating well for the missing output schema. However, it leaves the relationship to closely named siblings ambiguous.

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% and the single look_id parameter is fully documented with its pattern. The description adds no meaning beyond the schema about the parameter, so baseline 3 applies.

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 it retrieves 'One music video Look' along with the video it was saved from and the story's shots, distinguishing it from list_music_video_looks by scope. The phrasing is grammatically awkward ('One music video Look With the video...'), which slightly blunts an otherwise specific purpose.

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?

There is no explicit when-to-use guidance or named alternatives (e.g., get_look vs get_music_video_lookbook). Usage is only implied by the return-shape description and the note that both video and story are null while the video isn't public.

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