# compute_ditch

Paid tier only. Calling this without an authenticated CivilQuants account returns TIER_INSUFFICIENT — sign up at https://civilquants.com/pricing or use the free-tier alternative compute_manhole. Linear primary measurement of an open earthwork drainage channel — trapezoidal cross-section, four lining variants (unlined / geotextile / granular / concrete). Routes via CESMM4 Class E.4 (excavation for cuttings), NRM2 Group 34.10 (site works: open drains and ditches), MMHW Series 500.4 (SHW Cl. 514 Earthwork ditches and drains), SMM7 R13.4 (Land Drainage — ditches). Eight variant presets cover all four lining types x two characteristic size scenarios each. Unit: M. Second member of the drainage_ancillaries L2 leaf (opened at S32 with connection_to_existing). 20th use of the classed-then-legacy attribute discrimination pattern via the lining_type discriminator. The four standards genuinely diverge on which work-section heading owns ditches (Class E vs Group 34 vs Series 500 vs R13) — the platform renders all four honestly from one source WorkItem. Example params: run_length_m=100 m (1–1000), top_width_mm=1700 mm (200–10000), bottom_width_mm=500 mm (100–5000). Example call: {"params": {"run_length_m": 100, "top_width_mm": 1700, "bottom_width_mm": 500}, "standard": "MMHW"}. Omitted parameters use sensible engineering defaults. Pass deliverables=["xlsx","dxf","pdf"] (any subset) to also receive one-shot download URLs in the same call: Excel BoQ (both tiers, watermarked free) plus the dimensioned DXF (CAD) and PDF drawing sheets (paid tier).

Agent View of the PolicyLayer registry record for `compute_ditch`. HTML page: https://policylayer.com/tools/com-civilquants-civilquants/compute-ditch

## Facts

- Tool: `compute_ditch`
- Server: Civilquants (`https://api.civilquants.com/mcp`) — https://policylayer.com/tools/com-civilquants-civilquants.md
- Homepage: https://github.com/https://api.civilquants.com/mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 4 (1 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `params` | object | yes | Parameters for a single open-ditch primary measurement. The geometry is a trapezoidal cross-section run linearly along the ditch alignment. side_slope_h_per_v |
| `standard` | string | no |  |
| `output_mode` | string | no |  |
| `deliverables` | object | no |  |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "compute_ditch",
    "arguments": {
      "params": {}
    }
  }
}
```

## Why compute_ditch is rated High

The tool executes a server-side parametric computation (Bills of Quantities estimation) against external standards, triggering authenticated API calls on a paid tier. It is not a simple data retrieval (it actively computes and routes outputs), nor does it write/modify persistent data or perform financial transactions directly.

From the tool's own definition: "'Calling this without an authenticated CivilQuants account returns TIER_INSUFFICIENT — sign up at https://civilquants.com/pricing' and 'Linear primary measurement of an open earthwork drainage channel' — the tool runs a parametric estimating computation…"

Risk signals: High parameter count (11 properties)

## Use case

AI agents invoke compute_ditch to trigger actions in Civilquants. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Civilquants:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "compute_ditch": {
      "limits": [
        {
          "counter": "compute_ditch_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Civilquants (55)

- `compute_box_culvert` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-box-culvert.md
- `compute_combined_services_trench` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-combined-services-trench.md
- `compute_connection_to_existing` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-connection-to-existing.md
- `compute_embankment_cross_section` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-embankment-cross-section.md
- `compute_end_area_earthworks` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-end-area-earthworks.md
- `compute_gabion_wall` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-gabion-wall.md
- `compute_headwall_attenuation_outlet` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-headwall-attenuation-outlet.md
- `compute_highway_drainage_channel` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-highway-drainage-channel.md
- `compute_lighting_column` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-lighting-column.md
- `compute_multi_section_assembly` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-multi-section-assembly.md
- `compute_pad_foundation` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-pad-foundation.md
- `compute_parapet` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-parapet.md
- `compute_pipe_bedding` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-pipe-bedding.md
- `compute_reinforced_soil_wall` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-reinforced-soil-wall.md
- `compute_road_marking` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-road-marking.md
- `compute_single_service_run` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-single-service-run.md
- `compute_soakaway` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-soakaway.md
- `compute_soil_nailed_slope` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-soil-nailed-slope.md
- `compute_traffic_sign` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-traffic-sign.md
- `compute_utility_chamber` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-utility-chamber.md
- `compute_utility_kiosk_base` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-utility-kiosk-base.md
- `recompute_project` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/recompute-project.md
- `render_skill_report` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/render-skill-report.md
- `compute_attenuation_tank` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-attenuation-tank.md
- `compute_bored_pile_wall` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-bored-pile-wall.md
- `compute_cantilever_wall` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-cantilever-wall.md
- `compute_carrier_pipe_run` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-carrier-pipe-run.md
- `compute_catchpit` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-catchpit.md
- `compute_edge_drain` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-edge-drain.md
- `compute_flexible_pavement` — Read — https://policylayer.com/tools/com-civilquants-civilquants/compute-flexible-pavement.md
- …and 25 more: https://policylayer.com/tools/com-civilquants-civilquants.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-civilquants-civilquants · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-civilquants-civilquants