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

With no annotations, the description carries the full behavioral burden. It discloses a price, which is genuinely useful, but presents it as a flat "$0.68" while the schema implies WAV adds +$0.10 and duration is variable — leaving it unclear whether the quoted figure is a base rate or the total. Nothing is said about read-only behavior, rate limits, or whether the estimate is binding.

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 short sentences with the purpose front-loaded and no filler. The "Cost: $0.68" clause is compact, though it is arguably the most ambiguous element rather than the most informative.

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 estimation tool with no output schema, the description is minimally adequate. It omits the one thing an agent most needs to reason about cost — whether duration affects the price — even though a duration parameter with a 30–480 range strongly implies it does.

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 both parameters (duration, audio_format) are already self-documenting, including the WAV surcharge and the 30–480 second range. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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 ("Estimate the cost of music generation"), and the music qualifier separates it from estimate_cost and estimate_video_cost in the sibling list. It stops short of explicitly naming those alternatives, but the resource domain is unambiguous.

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?

There is no when-to-use guidance, no statement of when to prefer this over the sibling estimate_cost or estimate_video_cost, and no prerequisites (e.g., whether a duration must be known first). The description is purely a label plus a price.

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