speed

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

With no annotations, the description carries full burden. It usefully discloses that it re-encodes and that audio is retempo'd when a source audio track exists, but says nothing about quality loss from re-encoding, reversibility, or overwrite behavior beyond the schema.

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?

Two tight sentences, front-loaded with the core action and factor convention, with the audio behavior as a secondary note. Every sentence earns its place.

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 4-param re-encode tool with no output schema and full schema coverage, the description is adequate: it covers factor direction and audio handling. It could note re-encode quality/permissions, but nothing critical to calling it correctly is missing.

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 100%, so all four parameters are already documented. The description restates the factor semantics (>1 faster, <1 slower) already present in the schema and adds the audio-retempo behavioral nuance, but doesn't elaborate on output/overwrite beyond 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?

States a specific verb (change) and resource (playback speed by a factor) plus what it does (re-encode). It's clearly distinct from siblings like trim/concat/scale, though it doesn't explicitly name any alternative.

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?

Usage is only implied by the purpose statement — there's no explicit when-to-use, when-not, or named alternative (e.g. 'use scale/convert for X'). An agent can infer intent but gets no routing guidance.

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