Upload Image

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

Adds that files persist for 48 hours and return value is a list of URIs. Annotations don't contradict (readOnlyHint=false matches write operation). No mention of rate limits or failure modes, but context is good.

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?

Very concise: three sentences for purpose/usage, then args/returns in structured format. No superfluous text.

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?

Given single parameter and no nested objects, the description fully explains input, behavior, and output. No output schema needed due to clear description.

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, and description provides an example of the comma-separated path format, which adds practical guidance 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?

The description clearly states the tool uploads images to Gemini Files API and returns file URIs. It distinguishes from siblings by explicitly mentioning its use before gemini_batch_submit.

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 says 'Use this to pre-upload reference images before calling gemini_batch_submit' and explains benefit of avoiding base64 encoding. Lacks when-not-to-use or alternatives, but sufficient.

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