move_money_between_categories

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

With no annotations, the description carries the full burden and does disclose the core mechanic: source assigned amount decreases and destination increases by the same amount, scoped to a single month. However, it omits failure behavior (what happens if the source category has insufficient assigned funds), permission requirements, and whether the move is reversible or recorded elsewhere.

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: purpose and scope first, mechanism second, prerequisite last. No filler and nothing redundant with the schema.

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?

A mutation tool with no annotations and no output schema needs the description to cover behavior fully, and it covers the mechanics and the ID-lookup prerequisite adequately. It leaves out error conditions and the response shape, which the agent would need for a write operation of this kind.

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 all five parameters including defaults are already documented in the schema, establishing a baseline of 3. The description's $50 Child Support→Haircuts example slightly clarifies directionality of from/to, but adds no syntax or format detail beyond the schema.

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 (moves) and resource (budgeted money between categories) with the scope constraint (within the same month) and a concrete example. An agent can distinguish this from siblings like set_category_target or create_category without opening any schema.

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?

Gives the precondition for invocation (look up category_id values with list_categories first) and a usage scenario (covering a specific expense), which clearly orients the agent. It does not say when NOT to use this tool, e.g. across months or between budgets, so it stops short of the top score.

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