add_recurring

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

With no annotations, the description carries the full burden and does well: it explains that the expense posts on day_of_month, is tagged 'recurring', handles short months by using the last day, and posts immediately when the day has passed. It does not clarify whether immediate posting also still schedules future recurrences, which is a minor ambiguity.

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 compact and front-loaded. The first sentence states the core purpose; the following sentences add only high-value behavioral details. No filler or repetition.

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?

The description covers the main purpose, recurrence behavior, tagging, and edge cases. An output schema exists, so return values do not need to be described. It could be more complete by naming the one-time alternative explicitly, but the essential invocation context is present.

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?

The schema has 0% parameter description coverage, so the description must compensate. It adds meaningful semantics for day_of_month with scheduling edge cases, but amount, category, and merchant are only addressed by their self-explanatory names. No constraints, units, or formatting are provided for those parameters.

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 leads with a specific verb and resource: "Add a monthly recurring expense," with clarifying examples (rent, internet, subscriptions). This clearly separates it from one-time expense tools like add_expense and add_expenses in the sibling list.

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?

Usage context is implied: this is for monthly recurring expenses. However, there is no explicit statement of when not to use it or which sibling should be chosen instead, such as add_expense for one-time costs. The guidance is useful but left to inference.

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