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

The description adds real behavioral value — it discloses the 1,000-item ceiling and that entries are 'matched to card and account transactions,' which the annotations do not say. But 'Idempotent by action_id' directly conflicts with the declared idempotentHint=false, giving the agent two opposing signals on the single most consequential replay-safety question. The description also never states what happens to unmatched entries or whether the call is all-or-nothing.

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 short sentences, front-loaded with purpose before the field list and constraints. The parenthetical field enumeration is dense but necessary given the empty item schema, so it earns its space.

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 described, and the description covers scope, batch cap, matching, and item shape. It is missing error/partial-failure semantics and required-field guidance, which matter for a write tool ingesting up to a thousand records.

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% and the item schema is an untyped object with additionalProperties: true, so the schema alone tells an agent nothing about what to put in each element. The description compensates by enumerating the expected keys (agent, amount, currency, payee, purpose, rail, kind, card, run, action_id, at), which is essential information. It stops short of marking which of those keys are required or giving types/formats.

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 names the resource precisely ('actions agents took with money') and the temporal stance ('told after the fact'), so an agent can tell this is a retrospective batch-reporting tool rather than a live lookup. It does not explicitly differentiate itself from near-name siblings such as agent_action or month_end_actions, leaving that inference to the reader.

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?

'Told after the fact' implies this is for back-filling already-completed spend events, which is a usable usage cue. However, there is no explicit when-to-use versus agent_action/month_end_actions/import_csv, and no stated prerequisites (e.g., must the card or run already exist before an action can be matched?).

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