add_transfer

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

With no annotations, the description carries the full behavioral burden. It does disclose a genuine conditional trait (cross-currency requires both outcome_amount and income_amount, same-currency only outcome_amount/amount), but says nothing about auth requirements, side effects, reversibility, or confirmation for what is clearly a money-mutating operation.

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?

Three tight sentences with the core purpose front-loaded, followed by the currency-handling rule. Every clause carries information and there is no filler.

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?

For a 7-parameter mutating tool with no annotations and no output schema, the description covers purpose and amount handling but omits return behavior and the side effects/consequences of the transfer. It is minimally adequate rather than complete.

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 100%, so the schema already documents every parameter, including that amount is an alias and that income_amount is required cross-currency. The description largely restates this, though it does synthesize the two cases into a single decision rule.

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?

States a specific verb+resource ('Transfer money between two accounts in ZenMoney'), which cleanly separates it from the sibling write tools add_income and add_expense. It never explicitly names those siblings, so differentiation is implicit rather than spelled out.

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 cross-currency vs same-currency split is really a parameter rule, not a when-to-use/alternatives rule. There is no statement of when to prefer this over add_income/add_expense or of any prerequisites, so usage is only implied.

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