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

Annotations already indicate the tool is not read-only (readOnlyHint=false) and may have external effects (openWorldHint=true). The description adds the cost factor ($0.10 per image), which is useful, but it does not disclose output format, side effects, or any other behavioral traits. No contradiction with annotations.

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 exceptionally concise—a single sentence plus a pricing note—with no wasted words. The core purpose is front-loaded, and the cost is appended as a distinct, clear piece of 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?

For a simple tool with a single parameter and no output schema, the description is mostly sufficient. It lacks an explicit statement of the output (e.g., 'returns a repaired image'), but this is strongly implied. The cost and purpose are clear, making it adequate for correct invocation.

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 fully describes the image parameter (public https URL or base64 data URI) with 100% coverage. The description adds no additional parameter semantics beyond implying the image is the photo to repair, which is already evident from 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 states a specific verb ('Repair') with a clear resource ('scratches and damage in old photos'), which distinguishes it from sibling tools like unblur_image or upscale_image. The purpose is immediately understandable.

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 implies the tool is for repairing old photos but does not explicitly state when to use it over alternatives, nor does it mention any exclusions or conditions. Usage context is inferred rather than explicit.

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