firestarter_upload_image

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

Annotations indicate readOnlyHint=false and destructiveHint=false, covering the mutation safety profile. The description adds valuable context beyond annotations: a 6 MB size limit, the required base64 data-URI format, and the promise of a permanent public URL. It does not detail failure modes or auth requirements, but for a simple upload tool this is adequate.

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 compact and front-loaded with the essential purpose. It is organized into three logical sentences: what it does, when to call it, and input/output specifics. Every sentence adds necessary information, with no filler or repetition of schema details.

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 2 parameters, no output schema, and minimal annotations, the description is complete: it explains the input format, size limit, return value, and integration with other tools. It leaves no major ambiguity about how to use the tool or what to expect on success.

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% for both parameters, so the baseline is 3. The description adds extra meaning: it clarifies that the image must be base64 data-URI, mentions the 6 MB limit, and notes that the optional filename helps detect format (png, webp, gif). This goes beyond the schema descriptions, especially the size limit and the raw base64 prefix note.

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 tool's function: 'Upload a product photo the seller sent in this conversation and get back a permanent public URL.' It specifies the verb (upload), the resource (product photo), and the output (public URL). It also distinguishes itself from siblings by stating it should be called FIRST before firestarter_list or firestarter_update_listing, making its role unique.

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 explicit usage guidance: 'Call this FIRST when the seller provides a photo (attached image), then pass the returned URL into firestarter_list or firestarter_update_listing image_urls.' This tells the agent exactly when to invoke the tool and what to do with the result, effectively ordering it relative to sibling tools.

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