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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so 'Read-only' is partly redundant, but the description carries the real burden of disclosure since there is no output schema: it spells out the shape of the returned payload (params JSON schema, directorHint, beats, { spec, plan }). It adds no notes on size or stability of formats, which keeps it short of a 5.

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?

Front-loaded with the verb and resource, followed by a compact enumeration of return contents. It is a dense single sentence with an embedded list; every clause adds information, but the parenthetical stacking makes it slightly harder to scan than a short bulleted phrasing would be.

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 and no annotations describing return data, the description fully compensates by naming each returned section and what it is for, including the beats' sub-fields (id, what happens, duration, two-actor requirement). An agent can decide whether to call it and what to expect without further inspection.

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?

There is a single parameter with 100% schema description coverage, including an example ('dialogue@1') and its source ('Format id from list_video_formats'), so the schema already does the work. The description's only added signal about the id is implicit in naming sibling tools, so the high-coverage baseline of 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?

States a specific verb and resource ('Get one video format') and then enumerates exactly what the returned record contains: params schema, directorHint, beats (with their fields), and the { spec, plan } answer schema. This is clearly distinguishable from the sibling list_video_formats, which enumerates rather than describes a single format.

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?

'Use it to write or check a VideoSpec by hand' gives a concrete use context, and 'takes no title_id' pre-empts a likely wrong assumption. It does not explicitly state when to prefer plan_video or list_video_formats instead, so the alternative routing is only implied.

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