Upload file to Gemini Files API

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

Annotations indicate it's a write operation (readOnlyHint=false) and returns dynamic data (openWorldHint=true). The description adds return details (URI & metadata) and a usage condition, but doesn't elaborate on side effects or requirements beyond what the schema provides. With annotations present, the burden is partially met.

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 consists of two concise sentences. The first states the exact purpose, and the second adds a valuable usage condition. No unnecessary words or repetition.

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 tool has no output schema, so the description partially covers return values (URI and metadata). It addresses large file support, which is a key concern for uploads. Missing details like overwrite behavior or error conditions, but overall sufficient for typical use.

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% with descriptions for both parameters. The description does not add new semantic meaning beyond the schema; it confirms the path is server-accessible and display_name is optional, which is already documented. Baseline of 3 is appropriate.

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 a local file to the Gemini Files API and returns its URI and metadata. It distinguishes itself from siblings like generate_image by focusing on file upload rather than image generation.

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 specific context for when to use the tool: when the image is larger than 20MB or reused across prompts. It doesn't explicitly list alternatives or when not to use, but the context is clear and helpful.

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