MoveMoney

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

Goes well beyond the annotations: it warns that repeated invocation moves money repeatedly (reinforcing idempotentHint=false), explains the two-step source-then-destination implementation YNAB forces, and spells out the partial-failure outcome where funds land in Ready to Assign with a matching error. This is exactly the behavioral detail an agent needs before mutating budgets.

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 short, front-loaded sentences with no filler: purpose first, precondition second, failure semantics last. Every sentence carries information an agent would otherwise have to discover empirically.

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 non-idempotent mutation tool with an output schema and full parameter coverage, the description supplies what the structured fields cannot: the side-effect cadence, the two-call composition, and the degraded-failure state. Nothing essential to calling it correctly 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?

Schema description coverage is 100%, so the schema already documents month, amount, plan_id, and the from/to category IDs, including the 'omit to use Ready to Assign' semantics. The description confirms the source/destination direction of the move but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 and resource: 'Move money between two categories, or between a category and Ready to Assign,' and clarifies the mechanism ('adjusting their assigned amounts'). It is clear on its own, but it never names the nearest sibling Ynab_AssignToCategory, which an agent could easily confuse with this tool.

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 gives an implicit precondition ('The source must have at least the amount available') and describes the effect, but offers no explicit when-to-use guidance and no routing to or from the closely related AssignToCategory. Usage must be inferred.

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