Waffle Chart

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

Annotations already declare readOnlyHint=true and idempotentHint=true, ensuring the agent knows it's a safe read operation. The description adds the key behavioral constraint that values should sum to 100, which is not in annotations. No contradictions.

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, each earning its place: the first defines the tool and its visual form, the second adds the key constraint. No unnecessary words, well front-loaded.

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?

Given the complexity (6 params, no output schema) and the presence of annotations, the description covers the essential aspects: what the chart is, the data format, and a key constraint. It does not explain the return value, but for a render tool this is often implied.

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 100%, so the schema already documents all parameters. The description repeats the sum-to-100 constraint and adds the 10x10 grid context, but this does not significantly augment the parameter semantics beyond 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 clearly states the verb 'Render' and the resource 'waffle chart', specifies the 10x10 grid and proportional composition, and distinguishes from sibling chart tools like pie or bar charts by focusing on composition with a grid layout.

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 'What is the composition?' implies it's used for showing parts of a whole, but there is no explicit guidance on when to use it versus alternatives like render_pie_chart or render_bar_chart, nor any when-not conditions.

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