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

With no annotations, the description carries the full behavioral burden, yet it says nothing about lossy quality loss, where the compressed output is written or returned, whether the input URL must be publicly reachable, or any size/duration limits. Only the transformation and bitrate targets are disclosed.

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?

A single front-loaded sentence with zero filler, which is efficient and easy to scan. Its brevity is appropriate in form, though it is arguably under-specified rather than tightly scoped.

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 file-transformation tool with no annotations, no output schema, and half the parameters undocumented, the description should explain at minimum what the result is and where it goes. It leaves the return behavior and any constraints entirely unspecified.

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 50% (fileUrl documented, bitrate undocumented). The description merely restates the three enum values already present in the schema and adds no meaning about default behavior, format acceptance beyond MP3/WAV, or how bitrate interacts with input format. It does not compensate for the coverage gap.

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 (compress), a specific resource (MP3/WAV audio file), and the target bitrate options, so an agent can immediately distinguish it from siblings like compress_image, compress_pdf, and compress_video. Nothing about the core action is ambiguous.

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 description gives no when-to-use guidance, no indication of when an agent should prefer compress_audio over convert_mp4_to_mp3 or the other compress_* siblings, and no prerequisites. Usage must be entirely inferred from the name.

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