What information typically comprises a Tool's contract?

• A. Name, color, size, and owner.
• B. Name, description, input schema, output schema, and safety or usage constraints.
• C. Only the output schema.
• D. The tool's version number and last updated date.

Answer: (B)

A Tool's contract specifies the formal interface and safety rules for using it. It ensures the agent knows exactly how to call the tool, what information to provide, what will come back, and what constraints apply. The essential pieces include: the name used to identify the tool; a description that clarifies its purpose; an input schema that details required and optional inputs and their data types or structures; an output schema that defines the shape and type of the result; and safety or usage constraints that impose limits, guardrails, or requirements (for example allowed operations, rate limits, or preconditions). Together, these elements enable correct invocation, proper validation, and safe operation. The other options either pull in irrelevant details like color, size, or owner; or omit essential pieces like inputs and safety constraints; or focus only on the output without describing how to call or constraints.