Upscale or download Flow media at a larger size

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

With no annotations, the description carries the burden and does disclose meaningful traits: 2K is free on every account, 4K requires a paid plan, and the listing includes locked sizes. It does not say whether an upscale is reversible, whether it consumes credits, or whether the result is a download URL versus an async job — notable omissions for a mutation-like operation.

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 dense sentences, front-loaded with what the tool does and followed by the no-size fallback and one usage caution. Nothing is redundant, though the final sentence reads more as agent-directed policy than definition and could be tightened.

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?

Covers the modes, tier gating, and user-facing etiquette for a three-parameter tool with no annotations and no output schema. The main remaining ambiguity is the return shape — whether the call yields a file, a URL, or an asynchronous upscale job — which matters for a tool whose title mixes 'upscale' and 'download'.

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 only 33%, so the description must compensate; it adds the plan-gating meaning of '2k' vs '4k' and confirms the omit-to-list behavior. The two remaining parameters are conventional UUIDs (project_id, media_id) whose purpose is unambiguous from their names, so the uncovered portion is low-risk.

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 ('Downloads a project's media at the chosen size, upscaling it in Flow') and explicitly covers the dual mode: with size it downloads/upscales, without size it lists available sizes. An agent can distinguish this from flow_assets or generate_image without opening any schema.

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 clear conditional guidance ('Without size, lists the sizes...'), plan-tier context, and an explicit behavioral rule about offering the free 2K upscale to the user after new images rather than doing it unasked. It does not name sibling alternatives, but no comparable sibling exists for this operation, so the gap is minor.

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