Quote a personal actor

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

Annotations already declare readOnlyHint=true, and the description reinforces this by stating 'WITHOUT spending credits' and 'before any charge.' It adds substantial behavioral context beyond annotations: the per-format pricing model, the identity-check refusal before charge (actor_prompt_refused), and the note that failed formats are not charged. This gives agents a clear model of side effects and guarantees.

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 exactly two sentences, front-loaded with the core purpose and key constraint, followed by a critical cost nuance. No filler, no redundancy, and every clause contributes to agent decision-making. It is a model of conciseness.

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 description covers the essential behavior and usage, but it does not explicitly describe the shape of the quote response (e.g., whether it returns a total credit figure, per-format breakdown, or warnings). Given there is no output schema, a short mention of what the response contains would make this fully complete. Nevertheless, the agent can infer it returns a price, and the description already notes refusal behavior, so the gap is minor.

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% coverage; every parameter already has a description detailing constraints, defaults, and behavior. The tool description adds no additional parameter-specific semantics—it only mentions that formats are separately charged, which is already captured in the aspect_ratios parameter description. With full schema coverage, the baseline of 3 is appropriate.

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 a precise purpose: 'Estimate the credit cost of create_actor WITHOUT spending credits.' It clearly identifies the action (estimate), the target (credit cost of create_actor), and immediately differentiates from the sibling create_actor by stressing it does not spend credits. This is specific and distinct from any other sibling.

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 explicitly instructs when to use the tool: 'Call this first and show the price before create_actor.' It also warns that each requested format is a separate charge, giving the agent operational context. Though it doesn't list when-not-to-use, the positive directive is unambiguous and sufficient for this tool's placement in the workflow.

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