Upload a local file → durable public URL

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

Description adds context beyond annotations: it persists files, gives durable URLs, and details constraints like local-only path and dataUri size limit. Annotations already indicate non-readOnly and non-destructive. No contradiction.

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 thorough but somewhat lengthy; however, every sentence provides useful information. It is well-structured with clear sections for usage, constraints, and return value.

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 description fully covers the tool's purpose, usage, constraints, and return format. Given the output schema exists (mentioned as {url, kind, bytes}), no critical information is missing.

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%, so parameters are already described. The description adds valuable context: path works only locally, dataUri must be under 15MB on hosted connector, name helps extension selection.

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 persists an arbitrary user file (image or video, up to 150MB) and returns a durable public URL for use with sibling tools. It distinguishes itself by specifying when not to use it (if file already at public URL).

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 explains when to use (local file or dataUri) and when not (public URLs passed directly to siblings). Mentions the tool is for arbitrary files, not just render-related, and provides size limits for each source type.

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