Open image/audio upload widget

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

The description goes beyond annotations by clearly stating the widget cannot accept video/MP4, that it should never be used for video requests, and that for image-to-speech the user must enter exact text in the Script field. Although readOnlyHint is true and 'stage as durable assetId' hints at a side effect, this is not an outright contradiction since the tool itself may only open the UI. No mention of auth or rate limits, but annotations already cover high-level safety.

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 5 sentences and front-loaded with the primary action. Each sentence carries purpose, though some redundancy exists around video prohibitions. It is structured logically from core action to usage rules, alternatives, and special cases, but is slightly longer than strictly needed.

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 the simplicity of the schema (1 optional param) and presence of an output schema, the description is fully complete. It covers default usage, special image-to-speech behavior, exclusions, and fallback alternatives, leaving no missing context for an agent to misuse the tool.

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 already documents the requestedMediaType enum and notes video invalid, but the description adds significant context: when to use 'image' for image-to-speech, and the instruction to tell the user to enter exact requested text in the Script field. This goes beyond the schema description and directly helps correct 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 tool opens the Sync image/audio upload widget, allowing users to choose a ChatGPT file or upload a local image/audio file and stage it as a durable Sync assetId. It distinguishes itself from siblings by explicitly positioning it as the default for local uploads and contrasting with video-related tools.

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?

Provides explicit when-to-use (default for local image/audio upload when not attached to ChatGPT), when-not-to-use (video/MP4), and alternatives (attach to ChatGPT then call upload-media or create-lipsync). It also gives specific guidance for image-to-speech with requestedMediaType='image' and the Script field, leaving no ambiguity.

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