Generate a Before/After or A/B Comparison Chart

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

Annotations already indicate idempotent and non-destructive behavior. The description adds useful behavioral context by showing the exact output shape, providing an example, and noting that output_path saves a PNG. It does not contradict the annotations, and the readOnlyHint=false is consistent with the optional file-saving side effect.

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 well-structured and front-loaded: a one-sentence purpose, followed by compact Args documentation and a concrete usage example. Every part adds value, and there is no filler or repetition of schema fields.

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 9 parameters, nested objects, low schema coverage, and no output schema, the description is fairly complete: it documents all primary parameters with defaults and a full example. The only notable gap is not describing how response_format affects the return value, but the schema supplies that information.

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 low at 22%, but the description compensates by providing types, defaults, and an example for most parameters, including the nested group_a/group_b structures. It does not mention response_format, but the schema already describes that parameter with an enum and default.

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 states a specific verb and resource: it generates a side-by-side comparison chart for comparing two periods, campaigns, or A/B results. This clearly distinguishes it from generic chart tools like meta_generate_chart, though it does not explicitly name the sibling or contrast itself with it.

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 clear context for when to use the tool: comparing two time periods, campaigns, or A/B test results. It does not explicitly say when not to use it or name alternatives, but the use case is specific enough to guide an agent.

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