Create chart card

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

No annotations exist, so the description must disclose behavioral traits. It reveals the output format (SVG chart card) and included features but does not mention side effects, permissions, error handling, or the mutating nature of 'create'—particularly since it says 'Render' instead of 'Create.'

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 two concise sentences that front-load the primary purpose and usage, with no redundant or filler content. It is appropriately sized for the tool.

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 tool with 10 parameters and no annotations, this description is too sparse to support correct invocation. It omits chart-type-specific parameter expectations (e.g., series for bar/line, values for pie/donut) and does not clarify required data relationships or behavioral outcomes beyond the existence of an output schema.

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?

The description merely repeats the chart types from the schema enum and adds no detail about parameters like yLabel, subtitle, or the relationship between series and values. With only 50% schema description coverage, the description fails to compensate for undocumented parameters.

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 ('SVG chart card'), enumerates chart types ('bar, line, pie, or donut'), and distinguishes this from sibling card creators by highlighting chart-specific features like a legend and collapsible data table.

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 provides clear usage context with 'Use for useful graphics summarizing referenced data,' which indicates when to deploy this tool. However, it does not explicitly name alternative tools or state when not to use it, so it lacks full exclusion guidance.

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