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

The description adds substantial behavior beyond annotations: the link is one-time, expires in 30 minutes, supports files up to 500 MB, converts WebP to JPG/PNG, and returns fields such as upload_page_url, upload_url, and ticket_uid. These details are exactly what an agent needs before invoking a non-readOnly, non-idempotent tool.

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 dense but front-loaded and every sentence carries operational value: routing condition, return format, upload options, follow-up steps, size limit, and conversion behavior. There is no filler.

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?

Although there is no output schema, the description explains the relevant return fields and the full upload lifecycle, including polling with get_upload_status and reusing media_uid in create_post. Combined with full schema coverage, the definition is complete enough for an agent to invoke it correctly.

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 the schema already documents both name and workspace_uid. The description does not add parameter-level meaning beyond the schema, so the baseline score 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 states a specific action and resource: creating a one-time upload link for an image or video on the user's device. It also explicitly distinguishes this from the public-URL path used by sibling add_media_from_url, so an agent can select it confidently.

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?

It gives explicit when-to-use conditions ('user wants to post an image or video that is on their device, not at a public URL') and names the downstream alternatives/workflow: get_upload_status for polling and create_post for publishing. It also explains the two upload paths: user opens upload_page_url, or the agent POSTs to upload_url itself.

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