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

With annotations already covering read/write and destructive hints, the description adds substantial context: download links expire after 1 hour, the input is stored temporarily in Cloudflare R2 during the job, processing happens via a headless browser on ihateaudio.com, and the input is deleted when the job ends. It does not cover auth or rate limits, but it is strong on lifecycle and side effects.

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?

The description is front-loaded with the core purpose, then input, settings, output, and processing details. It is appropriately sized for a tool with nested parameters and a notable lifecycle, though the Cloudflare/R2 implementation detail is slightly more verbose than strictly necessary.

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, so the description correctly states that the tool returns download links and that they expire after 1 hour. It covers the required input, optional settings, output behavior, and temporary-file lifecycle, though it could mention supported preset values or error behavior.

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 schema already documents all four top-level parameters and the nested file object. The description repeats the settings keys and gives outputFormat examples, but it adds little semantic detail beyond what the schema already provides; the baseline of 3 is appropriate.

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?

The description states a specific verb and resource: 'Adds an echo or delay effect.' It distinguishes the tool from adjacent siblings like reverb_adder and slowed_reverb, so an agent can tell what effect this applies without opening 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?

It explains the required input shape (one file with a public HTTPS download_url) and optional settings, which implies when the tool is applicable. However, it does not explicitly say when to choose this over alternatives such as reverb_adder or slowed_reverb, nor does it state any exclusions.

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