ListTransactions

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

Adds substantial context beyond the annotations (which only cover readOnly/idempotent/non-destructive): the newest-first ordering, the sign convention for amounts (negative outflow, positive inflow), and the non-obvious behavior that split lines surface as separate rows typed 'subtransaction' when filtering by category or payee. These are exactly the traits an agent cannot infer from structured fields.

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?

Four sentences, each load-bearing: scope/ordering, filter exclusivity, amount sign convention, split-row behavior. The most decision-relevant information (what it lists, how to filter) is front-loaded with no filler.

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?

With read-only annotations and an output schema present, the description need not explain return values or safety. It covers ordering, filter rules, sign semantics, and split behavior — everything an agent needs to call and interpret this correctly.

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 100%, so the baseline is 3, but the description adds a real constraint absent from the schema: account_id, category_id and payee_id are mutually exclusive ('ONE of'). That mutual-exclusivity rule is genuine parameter meaning beyond the per-parameter schema text.

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?

Opens with a specific verb+resource ('List transactions') and immediately scopes it with ordering ('newest first') and filter conditions. The 'ONE of account, category or payee' clause distinguishes this bulk-list tool from the single-item sibling Ynab_GetTransaction. An agent can tell exactly what it gets back without opening the 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?

States a concrete usage rule — filters are mutually exclusive across account/category/payee — which guides invocation. It does not name alternative tools such as Ynab_GetTransaction or Ynab_ListScheduledTransactions, nor state when-not to use it, so it stops short of explicit routing.

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