Upload ad image

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

Annotations (readOnlyHint=false, etc.) are minimal; the description adds important behavioral context: it is a mutation that returns an AdImageHash, accepts two input modes, and enforces file constraints. It does not contradict annotations and provides useful transparency beyond them.

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 sentences totaling ~60 words. The description is front-loaded with the main purpose, then alternative inputs, then constraints. Every sentence adds value without redundancy or fluff.

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?

With no output schema, the description explicitly states the return value (AdImageHash) and links it to ad creation. It covers input options, constraints, and ad format requirements. For a simple upload tool, this is comprehensive and anticipates common agent needs.

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?

Although schema coverage is 100%, the description adds critical semantics: mutual exclusivity of url and imageData, server-side fetching for url, and specific format/size constraints (JPG/PNG/GIF up to 10 MB, landscape min 1080×607). These details are absent from the schema and greatly aid correct parameter usage.

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 clearly states the verb (uploads), the resource (ad image library), and the outcome (returns AdImageHash for use in ads). It distinguishes from siblings like get_ad_images or create_text_ad by specifying a unique action and purpose.

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 clear usage guidance: input options (public URL or base64), file formats (JPG/PNG/GIF), size limit (10 MB), and specific ad requirements (landscape min 1080×607). It lacks explicit 'when not to use' or alternative tools, but the context is adequate.

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