Plan (cost preview, no generation)

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

Annotations state readOnlyHint=true, idempotentHint=true, destructiveHint=false, which align with the description of a non-generating preview. The description adds valuable context: costs a fraction of a cent, Corent decides image/video/tier/aspect/duration, returns plan + cost, and handles unfulfillable requests with reason. No contradiction.

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 concise sentences with no filler. The purpose is stated upfront, and each sentence provides essential information: preview behavior, cost, decision factors, and fallback for unsupported requests.

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?

Given the tool's simplicity (one parameter, no nested objects, output schema exists), the description covers returns (plan, estimated cost, can_fulfill with reason) and edge cases (unsupported request types). No gaps for an agent to select and invoke correctly.

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% for the single parameter 'intent'. The description supplements the schema by providing an example ('a 10s vertical clip of a sunrise for TikTok') and explaining usage context (plain-language request, cost preview). This adds meaningful value beyond the schema's minimal description.

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 'Preview how Corent would handle a plain-language request WITHOUT generating anything'. It distinguishes from sibling tools like create, generate_image, generate_video by emphasizing no generation, and specifies the resource (plan/cost preview).

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 advises 'Use this to decide or confirm cost before spending.' It also provides examples of when not to use (audio, text, 3D, editing, real-world actions) and explains the can_fulfill false behavior with reason, giving clear when-to-use and when-not-to-use guidance.

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