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

Annotations already indicate non-read-only but non-destructive behavior. The description adds input formats (MP3/WAV) and fade-in/out capabilities, but does not disclose output format or processing quirks. This adds some value beyond annotations but lacks rich behavioral detail.

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 sentences, first is front-loaded with the action, second gives usage context. No filler words or redundancy.

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?

The tool has 9 parameters and no output schema. The description covers the core function and usage, but omits details about input options (URL vs base64 vs token), output behavior, and file size limitations. Schema fills parameter details, yet the description is minimally sufficient but not exhaustive.

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?

The input schema has 100% parameter description coverage, so the description need not explain parameters. It does mention fade in/out, but that overlaps with schema defaults. No additional meaning beyond the schema is provided.

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 'Trim a section of an MP3 or WAV file with optional fade in/out,' providing a specific verb, resource, and features. This clearly distinguishes it from siblings like converter or vocal remover.

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 explicitly says 'Use this when the user wants to cut a fragment from a longer recording,' giving clear context for when to use the tool. However, it does not mention alternatives or exclusions, so it falls short of a full 5.

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