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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered; the description adds real value by enumerating the response fields (width, height, aspect, fps, hasAudio, fileDurationMs, clipDurationMs) in the absence of an output schema. It stops short of describing edge cases such as clips with missing/offline media or how errors surface.

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 tool's identity and purpose, followed by usage, return shape, and siblings — a sensible ordering with no filler sentences. The trailing pointer to load_skill is slightly boilerplate but legitimately actionable.

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 inspector with no output schema, the description covers purpose, when to use, exclusion, and the exact return fields — enough to call it correctly. The only gap is the unexplained batched `items` path, which the schema carries alone.

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 description coverage is 100%, so the baseline of 3 applies. The description adds nothing about parameters — notably it never mentions the `items` batch form (max 20) or how `id` and `items` interact, leaving that entirely to the schema.

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?

A specific verb ('Inspect') plus resource ('a clip's underlying media file') and an explicit enumeration of the attributes returned (width/height, aspect, fps, duration, audio presence). It also names the sibling it is not (get_compound_children), so an agent can distinguish it without opening the schema.

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 before placing or scaling B-roll so you know its shape' gives the triggering context, and 'Not for a compound clip (use get_compound_children)' supplies an explicit exclusion with the alternative named. Related tools (get_timeline, set_clip_transform) further route the agent.

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