meta_ads_creatives_upload_image

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

Discloses that the image is persisted (mutating) and that Meta fetches once, so subsequent changes to URL don't affect the stored asset. Lacks details on authorization or file type constraints, but still valuable beyond the schema.

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 concise sentences, each adding value: action, output/use, behavioral trait, sibling distinction. No fluff; information 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?

Covers the main action, output, side effect, and alternative tool. Could be more complete with image format/size constraints, but for a simple upload tool it's quite thorough.

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 covers 100% of parameters with descriptions. The tool description restates some info (e.g., image_url being public HTTPS) but doesn't add significant new meaning beyond 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?

Clearly states it uploads an image from a public HTTPS URL and returns the image_hash. Mentions use in other creative creation tools, distinguishing itself from sibling tools like meta_ads_images_upload_file.

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?

Explicitly directs agents to use meta_ads_images_upload_file for local files, and implies this tool is for URL-based uploads. Also states the mutating behavior (image persisted in library).

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