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

Annotations already signal a non-read-only, non-destructive safety profile, lowering the bar. The description adds only 'using FFmpeg' as mechanism context; it does not disclose whether the original file is overwritten, where the output is written, or whether the operation is lossless versus re-encoded. The stream-copy behavior is mentioned in the file parameter schema, not the description.

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?

One front-loaded, single-purpose sentence with no filler. Minor redundancy: the leading title 'Trim Audio' restates the verb+resource of the following sentence, and the '[category: media]' tag contributes little value to an agent.

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 simple 3-parameter tool with 100% schema coverage, safety annotations, and no nested objects, the description plus schema is nearly sufficient for correct invocation. The main gap is explicit output file naming/overwrite behavior, which is only hinted at through the schema's note that an extension-less filename is treated as .mp3.

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 is 3. The description's 'start and end time' phrase loosely maps to the start/end parameters but adds no format guidance, default values, or constraints beyond what the schema already fully documents.

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 (Trim), resource (audio file), and the precise operation (specified start and end time), plus the mechanism (FFmpeg). This distinguishes it from near siblings like media_trim_video (video resource), media_extract_audio (extraction, not trimming), and media_merge_audio (merging, not trimming) without needing to open 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?

The purpose statement implies when to use this tool — when an audio file needs to be cropped to a time range — but the description offers no explicit when/when-not guidance or named alternatives. Given the direct sibling media_trim_video (which also handles audio tracks within video), an explicit exclusion would meaningfully help an agent pick correctly.

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