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

Beyond annotations (readOnlyHint=true, destructiveHint=false), the description adds that the tool is 'Free — never charged' and returns a job_estimate_id valid for 30 minutes. This discloses cost and validity aspects not covered by the annotations, enriching the agent's understanding without contradicting the structured hints.

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 three concise sentences: purpose, usage order, and return details. It is front-loaded with the primary action, has no redundancy, and every sentence adds value.

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 simple two-parameter tool with an output schema, the description covers purpose, invocation order, return value (cost and ID), and cost implication. It does not need to explain return format because the output schema exists, making this contextually 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?

Both parameters (audio_url and tools) are fully described in the input schema, including enum values and URL formats. The description adds no additional parameter-specific details, so the baseline score of 3 is appropriate given the 100% schema coverage.

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's purpose: 'Get the exact price to analyze an audio file before committing.' It specifies the resource (audio file) and the verb (get exact price), and distinguishes from sibling tools like analyze_track by framing this as a pre-commit estimate.

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 instruction 'Always call this first' provides clear when-to-use guidance relative to analysis. It doesn't explicitly name alternatives, but the directive strongly implies it should precede analyze_track. The context of 'before committing' further clarifies the intended use case.

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