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

Annotations already communicate non-read-only and non-destructive behavior. The description adds no extra behavioral context beyond the core detection purpose—e.g., no details on output format, limitations, or side effects. It is adequate but not enhancing beyond 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?

The description is two sentences, front-loaded with the primary action and use case. Every sentence earns its place with no filler 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 5 parameters, 0 required, and no output schema. The description explains purpose and usage context, and the schema covers parameter meanings. However, because the output schema is absent, the description could have mentioned the return format (e.g., BPM as number, key as string) to improve completeness, but the title and purpose make this largely implicit.

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 each parameter is already documented. The description itself does not add semantic detail about parameters, matching the baseline for high schema coverage. It doesn't clarify when to prefer audio_url vs audio_base64 vs file_token beyond what the schema states.

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 clearly states the tool detects BPM and musical key of an audio file with a specific verb ('Detect') and resource. It also explicitly lists the use cases ('tempo, key, scale or harmonic information'), distinguishing it from sibling tools that convert, trim, or split audio.

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 provides explicit usage guidance: 'Use this when the user asks for the tempo, key, scale or harmonic information of a song.' However, it does not mention when not to use it or refer to alternative tools for other audio analysis tasks, so it falls short of a 5 by the rubric.

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