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

Adds substantial context beyond the annotations: nothing is uploaded until the user picks files, the widget only renders in MCP Apps hosts like ChatGPT and Claude, files land at public URLs, and the box posts back a message of media URLs. It also discloses accepted formats and per-file size limits.

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?

Front-loaded with the purpose, then prerequisites and downstream usage. Slightly long due to the format/size inventory, but nearly every sentence carries operational 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?

An output schema exists so return values need no explanation, yet the description still explains the URL handoff to post-creation tools. For a widget-launch tool with one optional param, nothing an agent needs 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 description coverage is 100% and there is a single optional workspaceId whose semantics are fully documented in the schema; the description adds no parameter detail, so the baseline 3 applies.

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?

States a specific action and resource ('Show an upload box in the chat so the user can add photos, videos or documents') and clearly separates itself from upload_media and get_upload_urls, which it names.

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?

Gives explicit when-to-use ('when the user wants to post a file that has no public URL'), a fallback for unsupported environments ('elsewhere ask the user for a public URL and use upload_media'), and ties the result to the downstream create_post/update_post/bulk_schedule_posts calls.

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