export_canvas

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

With no annotations, the description carries the full burden and does well: it discloses where files are written, that annotation positioning/highlighting silently fails under file://, and that html inlines all artboards and libraries. However, it does not mention overwrite behavior or what the tool returns/confirms after writing, which would be useful for a file-export 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?

The purpose is front-loaded and nearly every clause contributes decision-relevant information. The text is dense and slightly run-on, mixing format tradeoffs and behavioral caveats in one paragraph, but it avoids fluff and is much more useful than a short generic sentence.

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 two-format file-export tool with no output schema, the description covers the essential choices, output structure, known failure mode, and similarity to render_canvas. The main gaps are overwrite semantics and any success/failure return value, which an agent might need to confirm the operation's result.

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 the baseline is 3, but the description adds real meaning beyond the schema: it explains the zip vs html format consequences in depth, the file:// caveat, and the automatic project-name-based file naming. It adds little for projectId or dir, but those are already well-described in the schema.

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 opens with a concrete action and resource: '把整张画布导出成一个文件，写到 outDir 下', then enumerates the two formats. It also differentiates from render_canvas by stating the same rendering logic is reused but persisted once, so export and preview cannot be confused.

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?

The description gives explicit format-selection guidance: zip is the default directory-tree export, while html is the self-contained, double-clickable option with tradeoffs explained. It contrasts with render_canvas and the browser export button, but it does not crisply state when to use export_doc or other siblings instead.

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