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

With no annotations provided, the description carries the full burden. It discloses important behavioral traits: output is 'saved to disk (file path in result)', the model and resolution are specified, and cost details are given ('$0.18 deposit per call', 'settles at actual model cost + 20%', 'no account needed', 'last run $0.075, ~80s'). This goes well beyond a safety-level annotation.

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 two sentences, front-loaded with purpose and workflow, then cost and timing. Every sentence earns its place; no redundancy or filler. It is compact yet information-dense.

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?

For a tool with no output schema and three parameters, the description covers purpose, workflow, output format (file path), pricing, and runtime. It does not discuss error scenarios or how to handle the payment flow, but the _payment_id parameter is well-documented in the schema. Overall, it gives enough context for an agent to invoke the tool successfully.

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% and the schema already documents each parameter. The description adds meaning by explaining the relationship between the upload and text ('upload -> text -> edit') and clarifies that the text is 'plain words'. This helps an agent understand that the Text parameter is the natural-language edit instruction, which is not fully explicit in the schema.

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 starts with 'Repaints an uploaded photo according to an edit described in plain words,' which clearly states a specific verb ('repaints'), resource ('uploaded photo'), and method ('edit described in plain words'). This distinguishes it from sibling tools like text-to-image (which generates new images) and photo-to-video (which animates).

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 phrase 'upload -> text -> edit' outlines a basic usage flow, implying this tool is for editing existing uploaded photos with a text instruction. However, it does not explicitly mention alternatives or state when not to use it, such as preferring text-to-image for new image generation. This is implied rather than clearly contrasted.

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