Tool Calling and Plugins for Railway and Highway Research

What the data for this category looks like

Data sources for railway and highway research reports include transportation authority monthly operation bulletins, industry association operation reports, regular announcements of listed transportation enterprises, and special research documents from third-party consulting institutions. Updates follow a primarily monthly regular release schedule. Immediate supplementary documents are issued when new lines open, freight rates adjust, or major policies take effect. Document structures typically include a core operation data section, a policy interpretation chapter, and a risk warning module. Fields include operation mileage (unit: kilometers), passenger and freight volume (unit: ten thousand person-times / ten thousand tons), freight rate (unit: yuan per ton-kilometer), construction progress percentage, and identifying fields such as specific line numbers and station names.

Constraints Imposed by These Characteristics on Tool Calling and Plugins

Railway and highway research report data sources are scattered. Multiple dedicated MCP tools must be called to pull content from different channels. The permission scope and execution order of tool calls must be clearly defined. Update rhythms vary across data sources. Some policy documents are updated immediately, while operation data is updated monthly. Incremental sync trigger conditions must be configured to avoid resource waste from repeated full data pulls. Field units and identification types are diverse. Raw data returned by tools must be uniformly formatted. For example, "operation mileage" fields with different expressions must be standardized to a standard unit, otherwise subsequent analysis will be affected. Individual research reports are lengthy. Content must be retrieved in pages during tool calls to avoid exceeding the LLM context window limit. Some operation data involves industry-sensitive information. Permission verification parameters must be configured to ensure only authorized call requests can obtain complete data.

Configuration Settings

Config Item	Recommended Value	Rationale
`mcp_server_url`	`http://127.0.0.1:8081/mcp/railway-report`	Points to the dedicated MCP service address for railway and highway research reports, to avoid confusion with tool calls for other categories
`tool_call_sequence`	`["fetch_policy", "fetch_operation", "fetch_summary"]`	Sorted by the priority of research report content. Obtain policy data first, then core operation data, then generate the research report summary
`field_mapping_rules`	`Operating Mileage: unit_km, Passenger and Freight Volume: unit_ten_thousand, Freight Rate: unit_yuan_per_tonkm`	Standardizes field units and naming across different data sources to eliminate data format differences
`update_trigger_interval`	`2592000 seconds`	Matches the monthly regular update cycle of railway and highway research reports, to reduce invalid call times
`context_window_limit`	`8000–12000 characters`	Adapts to the average length of individual railway and highway research reports, to avoid exceeding LLM context window limits
`error_retry_count`	`3 retries`	Addresses network fluctuations or temporary MCP service failures to ensure call stability

The parameter values provided on this page are common starting points for configuration. Actual values are affected by material form, data volume, and business rules. Specific issues require individual analysis. It is recommended to test on your own samples before finalizing settings.

Three Common Misconfigurations

Issue: MCP tool calls return 404 Not Found errors. Cause: mcp_server_url is not correctly configured to point to the dedicated service address, and a generic MCP service address is used instead.
Issue: Multi-tool call results are out of order, and research report content cannot be generated as expected. Cause: The tool_call_sequence parameter is not set, causing the LLM to select tool execution order randomly.
Issue: FastGPT fails to start after upgrading fastgpt-mcp-server, with a connection refused error in logs. Cause: The MCP service port changed after the upgrade, and the mcp_server_url configuration in FastGPT was not updated synchronously.

How to Verify Successful Configuration

Navigate to the FastGPT tool management page, view the configured railway and highway research report MCP tool, and confirm the status shows running.
Initiate a single test call, specify retrieving operation data for a main line railway, and check that the returned field values fully match the preset field_mapping_rules.
Trigger a manual update task, check the FastGPT backend logs, confirm there are no error-level log entries, and that the generated research report data includes the latest operation information.

Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-14.