asset_add

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

With no annotations provided, the description carries the full burden, and it delivers: it explains the side effect (copies bytes), the storage location (assets/<sha>.<ext>), the classification logic (magic bytes first), the fact it never edits a scene or creates a revision, and the local-only constraint. It also warns against using httpUrl or the original file path for embedding, which is critical for durability. This is exemplary transparency.

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 long but well-organized, with purpose, usage, return format, classification, and constraints in separate paragraphs. Every sentence adds value, though it could be tightened slightly without losing critical information. It is front-loaded with the core purpose and then expands into necessary detail.

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?

Despite having only one parameter, a nested source object, no output schema, and no annotations, the description covers everything an agent needs: return format, how to use the uri in edit, classification behavior, and the local-only limitation. It is fully self-sufficient for correct invocation.

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 0%, so the description must compensate. It does: it explains the source object's structure ({ path }), that path must be absolute and readable by the server, and that it is local-only. This adds meaning beyond the schema's terse description and fully clarifies the single parameter.

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 verb ('Add'), resource ('local image or font file'), and purpose ('so it can be used in a design'). It also differentiates itself from siblings by naming asset_search and asset_generate as the alternatives for finding and generating assets, and import for turning design files into designs. This makes the tool's role unmistakable.

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 explicitly contrasts with asset_search and asset_generate, and provides a clear when-to-use rule: use this when you have a file on disk. It also states when not to use it (never for placement, use edit) and points to import for a different scenario. This gives the agent unambiguous selection criteria.

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