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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond that: optimistic concurrency ('Revision checked'), default preview behavior, and the guarantee that the rest of the project is preserved.

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?

Three tight sentences with zero filler, and the core action is front-loaded ahead of the concurrency and preservation notes.

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?

An output schema exists so return values need no explanation, and the annotations plus description jointly cover the mutation and concurrency behavior. It is nearly complete for its complexity, though the roles of several identifiers remain unaddressed.

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 only 11% across 9 required params, so the description must compensate. It clarifies volume, fade in/out, expectedRevision (revision checked) and dryRun, but leaves itemId, projectId, workspaceId and idempotencyKey entirely unexplained in both places.

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 (adjust) and a precise scope (one item's volume and audio fades), which cleanly separates it from siblings like mute_clip_audio or timeline_audio_add. It does not name an explicit alternative, but the resource and scope are unambiguous.

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 mention that 'dryRun previews by default' implies a preview-then-apply workflow, giving implied usage. However, there is no explicit when-to-use vs when-not guidance and no routing to alternatives such as batch_update_timeline_clips for multi-item edits.

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