Upload a file to Luw.ai

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

Annotations already declare readOnly=false, idempotent=false, openWorld=true, destructive=false. The description adds genuinely useful behavioral context beyond that: uploads are normally unnecessary because other tools auto-upload, and the URL is reusable across tools. It does not restate the 12-hour auto-deletion (that lives in the schema) or discuss failure modes for unreachable URLs.

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 sentences, front-loaded with the primary purpose, then the caveat, then the exceptions. No filler and every clause carries decision-relevant information.

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?

No output schema exists, and the description compensates by stating the return value is a URL usable by every Luw.ai tool. Combined with full schema coverage and annotations, an agent has everything needed to decide and to call it.

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 100%, so source, persistent and persona_id are all fully documented in the schema itself. The description's mention of 're-host an image from a site Luw.ai can't reach' and 'store a file permanently' loosely maps to source and persistent but adds no format or syntax beyond the schema. 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 verb and resource ('Upload an image, video or 3D file to Luw.ai storage') plus the outcome ('get a URL usable by every Luw.ai tool'). This distinguishes it clearly from the many design/render/generate siblings, which produce content rather than host it.

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?

Explicitly frames scarcity of need ('Rarely needed: all tools already accept local paths and data: URIs and upload them automatically') and then names three concrete cases that do justify it: shareable URL, re-hosting an unreachable image, permanent storage. This is textbook when/when-not plus alternatives.

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