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

Annotations already indicate read-only, idempotent, non-destructive behavior, and the description reinforces this by stating it 'does not make payments, change accounts, fetch external data, or retain tool inputs.' This adds meaningful behavioral context beyond the annotations and contains no contradiction.

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 concise, front-loaded with usage guidance, and free of redundant wording. Every sentence contributes meaningful information: when to use it, what it returns, and what it avoids doing.

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 rich output schema and detailed input schema, the description provides sufficient context for an agent to decide when to invoke the tool. It explains the primary use case, the nature of the returned events, and key behavioral boundaries, so nothing essential is missing.

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 input schema is fully described with detailed parameter explanations, so schema coverage is high. The tool description itself adds little parameter-specific meaning beyond saying 'supplied figures,' but it does not need to because the schema already provides comprehensive semantics. This aligns with the baseline for high schema coverage.

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's purpose: it returns upcoming statement-related dates and explains timing questions like why closing date differs from due date. It uses specific verbs ('returns', 'calculates') and the resource is evident from the tool name and description, making it distinguishable from siblings focused on other tasks.

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 explicitly says when to use the tool ('Use this when someone asks about timing, what is coming up, or why the closing date differs from the due date') and clarifies what it does not do. However, it does not explicitly name alternative sibling tools or state when not to use it in favor of those, so it falls slightly short of full alternative guidance.

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