List every project-read-only GX3 CLI command this server will run, with a one-line summary of each. Read-only; touches no project. Call this before gx3_run_command when no typed tool fits, to see what is actually available rather than guessing a command name.

Trace a device's ON/OFF/hold conditions from exact ladder topology. MC master-control zone conditions are folded into the enable logic, and the output warns on multi-OUT-coil devices and rows below a conditional jump. The output carries each device's comment: keep every device paired with its comment when you report the result, and show the rung itself with gx3_ladder_print rather than describing it in prose.

Static satisfiability check: can two coils' ON/enable conditions be true at the same time? A 'mutually-exclusive' verdict is sound; a 'simultaneous-possible' verdict returns a witness assignment but is not a reachability proof.

Writers and readers of a device with POU name and real step. The first line carries the device comment; repeat it alongside the device in your answer instead of reporting a bare device number. Requires the xref DB: run gx3-cli xref build --root <root> once per project first.

Build conservative argument-level source-to-destination value-flow edges. Known transfer and other classified instructions produce edges with argument indexes, ranges, widths, execution condition, and confidence. Unknown or partially parsed operations are returned as unresolved records; no guessed edge is emitted. Device comments are included when available.

Run static review checks over the whole project and return a per-check summary with finding counts by severity. Checks: duplicate coils, multi-writers, alarm quality, unused devices, contradictory comments, linked-device writes, and signed/width/division type problems. Reads the project; WRITES one CSV per check plus a JSON summary into the working directory. Findings are advisory: a duplicate coil may be a deliberate SET/RST pair, so report the severity and let the engineer judge. Needs the index and xref DBs for the full check set.

Find logic that can never do anything: contacts that can never close, NC contacts on always-ON relays, coils and words written but never read, and SET latches with no matching RST. Returns findings grouped by kind with the device, its comment and where it appears. Reads the project; WRITES a CSV under the output directory. Devices refreshed from a network are excluded, since a remote station may be the real reader. Requires the xref DB.

Report, per device type, observed LD usage, density, and gaps in the index. Gaps are not verified free allocations: ST/FBD, unresolved accesses and external or reserved allocations are not excluded. Verify them in GX Works3 before adding devices. Read-only; returns a table and writes nothing. Requires the index-lite DB: run gx3-cli index-lite build --root <root> once per project first.

Inventory every alarm and fault device with what triggers it, whether it latches, any timer setpoint, and what resets it. Answers "what raises this alarm and how is it cleared" without reading the ladder by hand. Reads the project; WRITES a CSV. Interpret clearing from the hold type: a plain OUT clears when its enable logic goes false; SET-latched alarms require a reset path, and self-hold circuits require their seal-in path to drop or reset logic to act. Do not infer a power-cycle requirement merely from an empty RST list. Requires the xref DB.

Compare two versions of a project rung by rung and return what was added, removed or changed. Rungs are matched by their stable block GUID rather than by position, so inserting a rung does not report everything after it as changed. Use it to review what a revision actually did. Reads both projects; WRITES a detail CSV. Neither project is modified.

Map how this PLC is wired to everything outside it: IP addresses, CC-Link and SCON stations, and safety relationships, aggregated into one view. Use it to find which unit or remote station owns a device before assuming the program drives it. Reads the project and the comm detail CSVs; WRITES its own CSVs under the output directory. It does not communicate with any device -- everything is read from the project files.

Render a program in GX Works3 print-text layout. This is the output to show a user when explaining how a circuit is wired: quote it verbatim in a code block, never a JSON dump of the same rung. Output can be large; pass 'output' to write it to a file. To emit only the circuit under discussion, use 'list_sections' to discover section titles, then filter with 'section', 'pos_range' (A-B), or 'device'.

Match a captured device snapshot against the enable conditions the static trace produced, and say what the snapshot does not answer for. Reads files only: this never opens a PLC connection, and there is no MCP tool that does. Report the analysis state with the result -- a device the snapshot holds no value for comes back as 'no measured value; file only', and the rows that did evaluate are not the whole answer when that appears. One snapshot explains the instant it was captured, never the cause of a past stop or trip: do not use it to answer 'why did this trip earlier'.

Read an already-captured CSV/JSON device log offline: normalize it, emit per-device time series, list value change points, or export one instant as a snapshot for gx3_explain_snapshot. Reads files only and never opens a PLC connection. An imported or polled log is not a scan-synchronized recording: two devices that appear to change together may simply have been sampled together, so do not read ordering between devices out of it.

Escape hatch: run any MCP-allowed, project-read-only GX3 CLI command with explicit arguments. Project-mutating commands and local demo generation commands are rejected. Local artifacts are confined to GX3_MCP_OUTPUT_DIR. Prefer the typed tools above when one fits.