Add photos to a draft

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

The description adds a critical behavioral guarantee: 'Originals on disk are never modified or moved.' This goes beyond the destructiveHint annotation by specifying exactly what is protected. It also mentions Vinted's photo-count rule, giving useful behavioral context about the platform's constraints.

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?

Three concise sentences: the primary action, a safety guarantee, and a usage tip. Each sentence adds value without redundancy, and the main action is front-loaded.

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?

The description covers the core purpose, safety, and a practical use case. With two straightforward parameters, no output schema, and clear annotations, this is largely complete. Minor omissions like duplicate handling or return value do not detract significantly for such a simple tool.

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?

With 0% top-level schema description coverage, the description should compensate by explaining parameters, but it does not. It only hints that 'photos' are images to copy and 'draftId' identifies the draft. The nested schema descriptions for path and caption are present, but the overall parameter semantics are minimally addressed.

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 explicitly states the action: 'Copies more photos into an existing draft.' This clearly identifies the verb (copies), the resource (photos), and the target (existing draft), distinguishing it from sibling tools like delete_draft or publish_listing.

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 provides a concrete usage scenario: 'Vinted may block publishing higher-value items with fewer than 3 photos,' implying this tool should be used to add photos when a draft has too few. It does not explicitly name alternative tools, but the context is clear and actionable.

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