Move Money

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

The description goes well beyond the annotations by disclosing the non-atomic implementation: it reads both categories, rewrites both budgeted amounts, and explains the partial-failure response. This is exactly the kind of behavioral detail an agent needs and that annotations cannot express.

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?

Two sentences: the first states the core action and typical use; the second adds only high-value implementation and failure-mode details. There is no filler, repetition, or unnecessary background.

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 mutation tool with six fully documented parameters, the description provides the missing behavioral context: non-atomicity, partial-failure reporting, and the cover-overspending purpose. The only omitted detail is the exact success return shape, but the description's failure-mode disclosure compensates and no output schema is defined.

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 format/default, positive amount, plan/budget IDs, and category IDs. The description adds no new parameter-level semantics beyond restating the transfer direction, so the baseline of 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?

The description opens with a specific verb and direct object: 'Moves budgeted money from one category to another in a given month.' It also clarifies the motivating use case, covering overspending, and distinguishes itself from a plain category budget update by noting there is no single YNAB move endpoint.

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?

'Typically to cover overspending' gives a concrete triggering context, and the move-vs-set semantics imply when this tool is appropriate rather than a simple budget update. It does not explicitly name alternatives or exclusions, but the intended usage is clear enough.

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