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

Annotations already cover read-only/idempotency/destructiveness, but the description adds substantial operational context: it downloads from the public URL, stores the file in Cloudflare R2 during the job, processes via a headless browser, deletes the input copy, and returns links that expire after 1 hour. These are exactly the behavioral traits an agent needs beyond the annotations.

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?

Front-loads the purpose, then covers input, settings, output, and processing. It is somewhat long but well structured; each sentence carries useful information, though the infrastructure detail could be trimmed.

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?

There is no output schema, and the description explains the return links and their expiry, plus the processing lifecycle. It does not cover error cases or format restrictions, but for a media-processing tool with full parameter schema it is largely 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 coverage is 100%, so baseline is 3. The description enumerates the settings keys and gives examples for outputFormat, but adds little beyond the schema; it also says 'one file' while the schema permits up to 12 files, creating minor ambiguity.

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 and resource ('applies dynamic range compression') and names the effect ('to even out levels'). However, it does not differentiate from the sibling audio_compressor, so an agent cannot tell from the description alone when to choose this tool over that sibling.

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?

Provides input requirements and optional settings but no when-to-use guidance or alternatives. It never mentions audio_compressor or any condition under which this tool is preferred.

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