# compute_soakaway 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_attenuation_tank. Infiltration soakaway per CIRIA C753 Chapter 25. Granular-fill or modular-crate storage envelope with infiltration discharge through the base and side walls. Wraps attenuation_tank for the storage envelope and emits an INFILTRATION_SURFACE item plus optional PERFORATED_DISTRIBUTION_PIPE on top. Includes the C753 rational-method sizing engine with hot-spot and cold-spot factors of safety per C753 Tables 25.4 / 25.5; the engine refuses to size for VERY_HIGH hot-spot catchments (fuel forecourts, lorry parks) which C753 prohibits from direct infiltration without pre-treatment. Half-emptying time checked against the 24h C753 §25.4 limit. Renders cleanly across CESMM4 / NRM2 / MMHW / SMM7 using existing earthworks / drainage handlers plus the two new categories (INFILTRATION_SURFACE, PERFORATED_DISTRIBUTION_PIPE) added in S22. Example params: catchment_area_m2=500 m² (10–10000), rainfall_depth_mm=60 mm (10–300), measured_infiltration_rate_m_per_s=0.0001 m/s (1e-07–0.01). Example call: {"params": {"catchment_area_m2": 500, "rainfall_depth_mm": 60, "measured_infiltration_rate_m_per_s": 0.0001}, "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_soakaway`. HTML page: https://policylayer.com/tools/com-civilquants-civilquants/compute-soakaway ## Facts - Tool: `compute_soakaway` - 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 CIRIA C753 infiltration soakaway. Two ways to specify the design storm: (a) ``design_storm_volume_m3`` directly (from an upstream Mic | | `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_soakaway", "arguments": { "params": {} } } } ``` ## Why compute_soakaway is rated High This tool is a parametric estimating/computation engine that runs a sizing calculation (C753 rational-method), triggers external service calls with authentication checks, and emits structured bill-of-quantities items. It executes a computation pipeline with external API side-effects (authentication gating, tier validation, and output generation), placing it in the Execute category. From the tool's own definition: "'Paid tier only. Calling this without an authenticated CivilQuants account returns TIER_INSUFFICIENT' and 'Wraps attenuation_tank for the storage envelope and emits an INFILTRATION_SURFACE item plus optional PERFORATED_DISTRIBUTION_PIPE on top." Risk signals: High parameter count (30 properties) ## Use case AI agents invoke compute_soakaway 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_soakaway": { "limits": [ { "counter": "compute_soakaway_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_ditch` — Execute — https://policylayer.com/tools/com-civilquants-civilquants/compute-ditch.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_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