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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description reinforces it with 'Nothing is generated or charged' and adds context the annotations do not carry — pricing parity with the Brix36 create box and the creation of a draftId/quoteId for later reuse.

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 sentences, zero waste, front-loaded with what is priced before moving to return values and the no-side-effect guarantee. Every clause earns its place.

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 fields need not be spelled out, and the description still names the key returned identifiers. For a three-parameter read-only quote tool this is nearly complete; the only gap is the missing pointer to the confirm step that consumes the returned quoteId/draftId.

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 the prompt, draftId and attachmentIds semantics are already fully documented in the schema (including the repricing behavior of a reused draftId). The description adds no format, constraint or meaning beyond that, which is the expected baseline when the schema does the heavy lifting.

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 specific verb and resource: it 'prices one standalone picture from a text prompt and optional owned uploads.' The scope qualifier 'standalone picture' implicitly separates it from the more general studio_generation_quote and from studio_motion_quote / studio_storyboard_stills_quote, but no sibling is named explicitly, so the differentiation is inferred rather than stated.

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 line 'Nothing is generated or charged' tells the agent this is a pre-flight, non-committing call, which implies when to reach for it. However, it never names the follow-up tool (studio_image_confirm) or states explicitly 'use this before confirming a picture generation,' and there are no exclusions or alternative routing rules.

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