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

Annotations already declare destructive=true, idempotent=true, readOnly=false. The description adds genuine context beyond them: optimistic concurrency ('Revision checked'), default preview behavior via dryRun, and the workspace-scoping constraint on the asset. It does not say what a revision mismatch does, but the added disclosure is substantive.

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 short sentences, all front-loaded: action and scope first, then revision/preview behavior, then preconditions. No filler and nothing buried.

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 destructive mutation tool the description covers the critical agent-facing facts (concurrency check, preview default, prerequisites), and an output schema exists so return values need not be described. Minor gap in not stating the failure path on a revision mismatch, but it is close to complete.

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 29% across 7 required params. The description clarifies dryRun (previews by default), expectedRevision (revision checked), and workspaceId (same workspace as the asset), but leaves itemId, assetId, projectId, and idempotencyKey entirely to the schema. Partial compensation for a low-coverage 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?

States a precise verb+resource ('Replace one shot's media asset') with an explicit scope constraint ('while preserving the other timeline items'), which separates it from siblings like editor_assets_insert or update_timeline_clip. An agent can tell what it mutates 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?

Gives real preconditions for use: a current editor snapshot must exist and the asset must be in the same workspace, plus dryRun previews by default. It does not name a competing sibling tool to route against, so it falls short of full when/when-not guidance.

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