find_unusual_transactions

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

With no annotations provided, the description carries the full behavioral burden, and it does add real content by defining 'unusual' as above-normal for category plus possible double charges. It does not state that the tool is read-only, what threshold or heuristic defines 'usual', or whether results are ranked or capped. An output schema exists, so return shape needn't be explained, but the detection logic remains opaque.

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?

A single sentence with no filler or repetition, and the defining criteria are front-loaded. It is arguably too terse to be actionable, but that shortfall is a completeness problem rather than a verbosity one.

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 tool has a non-trivial analytical purpose, one undocumented optional parameter, and no annotations, yet the description is one clause long. It should explain what makes a transaction 'unusual' (threshold, comparison period) and what `month` controls. The output schema covers return values, but essential call semantics are 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 0%, and the single `month` parameter appears nowhere in the description. An agent cannot tell from the text whether `month` scopes the analysis window, is required, or defaults to the current month (the schema only shows a null default). The description does not compensate for the schema gap.

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?

Names a specific capability: finding transactions that are unusually large for their category, plus possible duplicate charges. This is more informative than a generic 'find transactions', and it is implicitly distinct from search_transactions and spending_by_category. However, it never explicitly contrasts itself with siblings, so the differentiation is left to inference.

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?

There is no statement about when to use this tool vs. search_transactions, find_subscriptions, or forecast_month. The single sentence describes what the tool finds but gives no trigger conditions, prerequisites, or exclusions. An agent would have to guess when this tool is the right choice.

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