What the documents look like
Producer export tax refunds that combine domestic-sales tax offsets with export refunds require comparison work to run across two data sets within the same filing period: domestic sales and exports. The main data sources are the electronic tax bureau, ERP sales records, customs electronic information, and financial ledgers. The recurring documents are the exemption, offset, and refund filing detail schedule, export contracts, sales detail ledgers, and export customs declarations. The task of comparing contracts against transaction materials is to match the transaction information recorded in an export contract against the customs declaration, the sales detail ledger, and the filing detail schedule, item by item, and to confirm that the entity, the object, the period, and the amount basis agree. Data updates monthly, and comparison is also aggregated monthly.
Two features of this category shape how tool calls are used here. First, because domestic-sales tax offsets and export refunds are calculated together, a contract comparison cannot be treated as an isolated document check; the contract amount must be read against the same filing period's sales ledger and filing detail schedule. Second, the contract, the customs declaration, and the ledger carry different field formats, so a tool that reads a contract amount produces a value that still requires field-level human comparison against the ledger, not an automatic conclusion.
Constraints at the tool calls step
The tools available to the tool call module are determined jointly by the tool description and the tool parameters. The description states the tool's purpose. Parameters distinguish fixed parameters of system modules from configurable parameters of plugins. When a parameter is required and no suitable value exists in the context, the model may not call the tool; prompts can guide the user to supply the parameter, and the actual request governs. In advanced orchestration, connecting a tool to the tool call module allows editing the description to narrow the call timing; the official guidance recommends starting with a small number of tools, tuning them, and then adding more. The tool call termination node ends the current call, so no further tools are called and no AI summary of tool results is produced.
Hypothetical drill sample: for a producer enterprise's March 2026 filing period, an export contract numbered HT-2026-03-07 states "seller is Company A, buyer is Company B, goods are self-produced A-type fittings, quantity 1000 pieces, trade term FOB, total price USD 120,000, signing date March 2, 2026." The same month's sales detail ledger records "March 7 export of A-type fittings, 1000 pieces, amount USD 120,000." The pending handoff request reads: "Please call the contract-reading tool, compare this contract amount with the sales ledger amount, and if they agree, write into the filing detail schedule." In this request, "write into the filing detail schedule" is a business action requiring a separate downstream implementation; the tool call itself performs no database write.
Configuration and implementation checks
| Configuration item | Hypothetical starting point for this trial | Check method and reason |
|---|---|---|
| Tool description | States that it reads the export contract amount field | The description determines whether the model calls the tool; it should state input conditions and situations where calling is inappropriate |
| Required parameters | Contract number, filing period | When no suitable value exists, the model may not call; complete through interaction and check the actual request |
| Tool connection | Only the contract-reading tool is connected | Start with a small number of tools to observe whether call timing is precise |
| Termination node | Placed after the contract-reading tool | After termination, no further tools and no AI summary are called; check whether output is returned directly |
| Custom tool variable | Parameter description filled for the filing period | Nodes not treated as tool parameters can be called through this route |
| Manual comparison action | Compare amount and quantity fields | Tool return values are compared field by field against the sales detail ledger; this is not treated as authorization to write |
The starting points above are trial settings for this hypothetical exercise and are not official default values. A single contract-reading tool is chosen so that call timing can be compared against the guidance to tune a small number of tools first.
Three common errors
- Treating the tool description as a guarantee of execution. The description only tells the model the tool's purpose; whether the tool is called also depends on whether parameters are complete. Check: input the sample's contract number and filing period, observe whether the actual request carries both parameters, and record non-call when parameters are missing.
- Treating the tool return value as authorization to write. The sample request contains "write into the filing detail schedule," an action requiring downstream implementation. Check: verify whether the tool output is only a read result, whether the business write has a separate implementation, and record the gap when it does not.
- Treating retrieval or similarity as a permission filter. Tool calls do not perform entity isolation. Check: confirm whether the call scope is limited to targets with access rights; when this is missing, record the evidence gap rather than inferring that unrelated records are excluded.
How to verify the setup
- Verification one: input the sample contract text and the sales detail ledger text, and compare whether the amount field USD 120,000 and the quantity 1000 pieces agree on the same entity, the same period, and the same field. When the two agree, the comparison condition is met; when they do not, record the differing field and do not draw conclusions beyond the discrepancy.
- Verification two: input the pending request text and compare whether the actual tool request contains the contract number and the filing period. When the request carries both parameters and calls only the contract-reading tool, the condition is met; when a required parameter is absent, record that the model did not call.
- Verification three: input the termination node configuration and the tool output, and compare whether an AI summary or a subsequent tool call still appears after termination. When there is no subsequent call and the output is a read result, the condition is met; when a write action appears, record it as a business action requiring separate implementation.
For empty-result handling, a paper input of [] can be used to check downstream design, without claiming that a fictional rule search necessarily returns []. Libraries across different vector models cannot be associated together; check identifiers only and exclude those that do not match.