chart_export

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

Annotations already supply idempotentHint, readOnlyHint=false, and destructiveHint=false, lowering the burden. The description adds helpful behavioral details: output formats, the self-contained nature of HTML (vega js inlined, offline-capable), and the collision-refusal behavior. No contradiction with 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?

Two sentences, front-loaded with the action, and every phrase adds meaning (formats, self-contained HTML, collision behavior). No wasted words.

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 small export tool, the description covers purpose, output types, and a key safety behavior. Still, it leaves gaps: no mention of scale, no explicit relationship between out_path and extensions, and no hint about what happens beyond refusal. Given moderate complexity and no output schema, this is minimally adequate.

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 0%, so the description must compensate, and it does partially: mentioning formats clarifies image_format, and 'out_path' collision clarifies that parameter. However, it does not mention 'scale' or explicitly map spec_path to the input, leaving some parameter semantics unexplained.

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 uses a specific verb ('Render') and resource ('existing .vl.json') and lists output formats (svg, png, self-contained html), making the tool's primary purpose clear. It also implies differentiation from siblings like chart_spec by emphasizing 'existing', but it does not explicitly name an alternative tool.

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 phrase 'existing .vl.json' implies the tool should be used after a chart spec exists, which gives some context. However, there is no explicit guidance about when to choose chart_export over sibling tools, nor exclusions.

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