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

Annotations declare non-destructive and idempotent, and the description adds real behavioral context beyond them: the quote is fixed and expiring, it binds the current lyrics/selections, and billing is ceil(seconds) per edit. It does not disclose auth/permission requirements, but the lifecycle semantics are unusually well conveyed.

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?

Short and front-loaded: the key non-spending constraint leads, then the binding rule and the handoff instruction. The 'Cost is ceil(seconds) per edit' fragment is awkwardly placed but earns its space as pricing context.

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?

An output schema exists, so return values need not be described, and the spend/quote workflow is covered. The gap is on the input side: with four required parameters and no schema descriptions, several parameters are left semantically undefined.

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 0%, so the description carries the full burden, yet only max_credits is explained ('the user's authorized ceiling'). edit_ids is hinted at via 'binds current lyrics/selections', but project_id and idempotency_key get no semantic coverage in either place.

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+resource ('Get a fixed expiring quote') and immediately scopes it as non-spending, which separates it from the spender sibling generate_changes. Remains somewhat terse about what a quote actually is, but the resource and its lifecycle are identifiable.

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?

Explicitly tells the agent when to re-quote ('changing an edit requires a new quote') and what to do next ('Pass its id to generate_changes to spend'), naming the alternative tool and the handoff condition. This is complete routing guidance.

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