Analysis — Overspent history

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

Annotations only cover the safety profile (readOnly, non-destructive, closed-world), and the description goes well beyond that: the cash-vs-credit inference and why YNAB cannot report it, the downstream effect on next month's Ready to Assign, and the per-month request cost model. This is exactly the extra behavioral context annotations cannot carry.

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?

Front-loaded with '[READ]' and the core return shape, followed by the conceptual cash/credit explanation and then the cost caveat. Dense but every clause carries information; the cash/credit mechanism paragraph is the only mildly padded part.

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?

An output schema exists so return values need not be spelled out, yet the description helpfully summarizes them anyway. Cost, limits, and date formats are covered; the only real gap is the semantics of plan_id and include_hidden for a 4-parameter tool.

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 coverage is 0%, so the description must compensate. It does document accepted formats for from_month/to_month ('YYYY-MM', ISO date, or 'current'), but says nothing about plan_id or include_hidden, leaving half the parameters undocumented in both schema and description. Minimum-viable rather than complete.

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 (overspent/inference history) and explicitly scopes it 'across a range', which implicitly separates it from the single-period sibling analysis_overspent_categories. It also enumerates what is returned (negative month-end balances, cash/credit flags, running total, most-overspent categories). It misses an explicit disambiguation sentence naming the sibling, so it falls short of a 5.

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 a concrete operational precondition ('check overview_request_budget before a long range') and states the 36-month cap, which tells the agent when the call is expensive. However it never states when to prefer this over analysis_overspent_categories or the month-scoped alternatives.

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