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

Annotations already declare readOnlyHint and destructiveHint=false, so safety is covered; the description adds genuine context beyond that: no charge is incurred, the returned payload includes quoteId/job facts/result size, and quotes expire after ~5 minutes. The expiry and no-charge facts are exactly the behavioral detail an agent needs before quoting.

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?

Four tight sentences, front-loaded with the core purpose, then the non-charge caveat, the prerequisite, and the return/expiry facts. No filler; each sentence carries distinct information.

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 spelled out, yet the description still names the key returned fields. Combined with prerequisites, non-charge, and expiry, the definition is complete for a quoting tool; only the explicit follow-up-to-generate linkage is left implicit.

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 schema already documents all six parameters in detail (enum meanings, factor/quality/variations constraints). The description adds no parameter-level meaning beyond what the schema provides, so the baseline 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?

States a specific verb (quote) and resource (one Paint Lab AI action on an uploaded image), and immediately differentiates from the generate sibling by clarifying 'Does not generate or charge.' An agent can tell this is a pre-flight cost/quote step, not the generation itself.

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?

Gives the prerequisite flow explicitly: upload first with presign_generation_asset and complete_generation_asset. It also signals this is a non-executing step. It stops short of naming generate_paint_lab as the follow-up call that consumes the quoteId, so the full when-to-use path is only implied.

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