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

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds that operations are 'não-destrutivas' (non-destructive) and clarifies account prefix restriction. No additional details on error handling, rate limits, or idempotency beyond the annotations.

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 front-loaded with the main action and uses bullet points for clarity. However, it includes details about other actions that are not core to this specific tool, making it somewhat less concise.

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 (4 parameters, no output schema), the description covers the main action, required parameters, and bulk support. It lacks information on return values, error conditions, and precise data formats, leaving some gaps for an agent.

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 0% schema description coverage, the description compensates by explaining that 'data' should contain 'due_at' for update_due_date, and that 'charge_ids' is for bulk execution. However, it does not specify formats, constraints, or elaborates on all parameters (e.g., 'account').

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 explicitly states it operates on Pagar.me V5 charges and lists the specific action 'update_due_date' (flattened). It distinguishes from sibling tools like capture, confirm, retry by naming the action, though the inclusion of other actions may cause slight confusion.

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 context: it is for accounts starting with 'sk_', requires charge_id, and supports bulk via charge_ids. However, it does not explicitly state when to use this tool over alternatives or when not to use it.

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