add_transfer

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

Annotations already indicate a write operation (readOnlyHint=false), but the description adds valuable behavioral context: the need for user approval, the distinction between cross-currency and same-currency behavior, and the alias relationship between amount and outcome_amount. This goes beyond what annotations provide, though it doesn't describe the response or side effects in detail.

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 three sentences long, immediately states the core purpose, and each sentence provides necessary information. There is no redundancy or wasted words, making it highly efficient and well-structured.

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 tool has 7 parameters and no output schema, the description covers the key complexities (currency handling, approval requirement) but does not mention what the response contains or any prerequisites like account existence. However, the essential usage for an agent is covered, and the missing return details are partially mitigated by the absence of an output schema.

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?

While the schema covers all parameters (100%), the description adds essential context: it explains the relationship between outcome_amount, income_amount, and the amount alias, and specifies when each is required. This integration of parameters into usage rules significantly enhances understanding beyond the individual schema descriptions.

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 function: 'Transfer money between two accounts in ZenMoney.' This distinguishes it from sibling tools like add_expense and add_income, which handle single-sided transactions. The verb 'transfer' and resource 'two accounts' are specific and immediately clear.

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 clear context on how to handle cross-currency vs same-currency transfers, which indirectly guides the agent on parameter usage. It also explicitly states 'Codex must request user approval before calling this tool,' which is a crucial usage requirement. However, it doesn't explicitly compare with alternative tools or state when not to use this tool, so it lacks explicit exclusions.

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