Pie Chart

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

Annotations already indicate readOnlyHint=true and idempotentHint=true. The description adds 'interactive' and 'Supports themes for styled visuals,' which are non-obvious traits not covered by annotations, adding meaningful behavioral context beyond the structured fields.

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 extremely concise, consisting of two sentences that front-load the core purpose and essential input format, with no wasted text.

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?

The description covers the core purpose and input format, but given the complexity (7 parameters, many siblings, no output schema), it lacks detail on output format (e.g., image URL or embedded chart) and does not sufficiently differentiate from the large set of sibling tools.

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?

With 86% schema description coverage, the baseline is 3. The description mentions 'key-value pairs' and 'themes,' which are already detailed in the input schema, so it does not add significant new meaning beyond what the schema provides.

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 clearly states the tool renders an interactive pie or donut chart from key-value data, using a specific verb ('render') and resource type, which distinguishes it clearly from sibling chart tools like render_bar_chart or render_line_chart.

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 implies usage for key-value data with pie/donut charts but provides no explicit guidance on when to use this tool versus alternatives, lacking when-not-to-use or exclusion conditions.

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