Open an interactive map so the user can draw GIS geometry, then capture it.

Returns a Prefab app with (1) a link that opens a Leaflet drawing page in the browser and (2) a "Load drawn geometry" button. Workflow:

1. Call this tool (optionally center it with lat/lon/zoom).

2. The user clicks "Open drawing map", draws a polygon/line/point, clicks Save.

3. The user clicks "Load drawn geometry" (or you call gis_get_drawn_geometry with the session_id) to retrieve a compact GeoJSON string.

4. Pass that GeoJSON to nfhl_screen_flood_zone, hydro_find_waterways, etc.

Use when: "let me draw a shape / area on a map", "I want to sketch a polygon". Don't use when: the user already has coordinates (use gis_validate_geometry).

The returned app also surfaces the session_id in text so the agent can call gis_get_drawn_geometry directly if the user prefers not to click the button.

Retrieve the geometry a user drew and saved on the interactive map.

Call this after gis_open_map once the user has drawn a shape and clicked "Save" on the map page. Geometry stored by the map is already validated and normalized (WGS84, closed rings). The returned "geometry" string can be passed directly to nfhl_screen_flood_zone, hydro_find_waterways, and other geometry-accepting GIS tools.

Use when: "I drew a shape, get it", or wired to the "Load drawn geometry" button inside the gis_open_map app.

session_id handling:

• If you know the exact id from the latest gis_open_map result, pass it.

• If you don't have it (e.g. a later turn), OMIT session_id entirely and the most recently saved geometry is returned. Never pass a placeholder like "default" — that will fail.

Returns when a shape has been saved: { "ready": true, "session_id": str, # the resolved session id "geometry": str, # compact GeoJSON string, ready to paste downstream "summary": { geo_type, crs_epsg, vertex_count, part_count, bbox, ... } }

Returns when nothing has been saved yet: { "ready": false, "message": "No geometry saved yet ..." }

Error responses:

• {"ready": false, "error": "Unknown or expired session ..."} — bad session_id.

Validate and normalize a GeoJSON geometry string for use with GIS servers.

Checks that the geometry is a supported type with valid WGS84 [lon, lat] coordinates, unwraps Feature/FeatureCollection wrappers, and closes any unclosed polygon rings. Returns a compact, single-line GeoJSON string that can be passed directly to the FEMA NFHL (nfhl_screen_flood_zone) or USGS National Map (hydro_find_waterways, etc.) tools.

Use when: you already have coordinates/GeoJSON and want to confirm it's valid and correctly formatted before querying another GIS server. Don't use when: you want to draw a shape interactively (use gis_open_map).

Returns on success: { "valid": true, "geometry": str, # compact GeoJSON string, ready to paste downstream "summary": { # geo_type, crs_epsg, vertex_count, part_count, ... # bbox [minLon,minLat,maxLon,maxLat], approx area/length } }

Error responses:

• {"valid": false, "error": "..."} — invalid JSON, unsupported type, out-of-range coordinate (e.g. swapped lat/lon), or malformed BoundingBox.