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

Annotations already declare idempotentHint=true, destructiveHint=false and readOnlyHint=false, so safety behavior is largely covered. The description usefully adds that null values remove a fade and that the edit result is returned, but says nothing about whether an existing fade is overwritten or what the fade curve looks like.

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, front-loaded sentences with no wasted lead-in. The parenthetical pointer to server instructions is the only mildly expendable element.

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 and return values are correctly deferred, so that is not a gap. However, for a 5-parameter mutation tool with only 40% schema coverage, the definition leaves units, defaults, and partial-fade behavior unexplained.

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 40%, so the description must compensate somewhat. It clarifies the null semantics for in_frames/out_frames and ties them to start/end of the clip, but never states that values are frame counts, their defaults, or what happens if only one side is given.

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?

Names a specific verb (fade) and resource (a clip's sound), and specifies the effect direction: in from start, out to end. It is distinguishable from siblings like audio.set_gain or transition.add, but it never explicitly contrasts itself with those neighbors.

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 sentence 'null removes a fade' gives one clear when-not case, which is genuinely useful. There is no guidance on when to fade instead of using audio.set_gain or a transition, and no prerequisites are stated.

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