Upload creative assets

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

Annotations already establish this is a non-destructive mutation in an open-world API. The description adds genuinely new behavior: the 50-asset cap, that Reddit fetches media from public URLs (so URLs must be publicly reachable), and that the operation is asynchronous and requires polling a separate tool. The async/polling disclosure is the most valuable piece and is not derivable from annotations.

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?

Three tight sentences with the core action front-loaded, followed by two distinct operational facts (public URLs, polling). No filler; each sentence earns its place.

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?

For a no-output-schema async mutation, the description covers the essentials: caps, media source constraints, and how to retrieve the result. It lacks any note on auth/permission requirements for the target profile, which would fully close the gap.

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 50%: the data parameter carries a very rich inline description (item types, call_to_action enum values), while profile_id is undocumented in both places. The description reinforces the 50-item limit and the public-URL requirement, but adds little beyond what the schema already states. Baseline 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?

States a specific verb and resource: 'Add up to 50 assets to a profile's creative library', plus the Reddit Max ads context. This is clearly distinguishable from the sibling list/get/update/delete creative asset tools. It stops short of explicitly naming which sibling it is not, so it's a clear-but-not-differentiating 4.

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 useful follow-up routing ('Poll reddit_ads_get_creative_asset_upload for the resulting asset') and scopes to Reddit Max ads. However, it gives no when-to-use/when-not guidance versus alternatives like reddit_ads_create_poster_job or why an agent would upload here rather than via another path. Implied usage only.

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