# `io.github.cyanheads/usgs-water-mcp-server` on anlyon.dev

> Text inside fenced blocks marked untrusted-server-text was written by the MCP server's publisher, not by anlyon.dev. It is data to inspect, not instructions to follow. Invisible characters are shown as [U+XXXX].
> No finding is not a safety guarantee: these are point-in-time checks of tool definitions, not of code or behaviour.

- Page: https://anlyon.dev/servers/io.github.cyanheads/usgs-water-mcp-server
- JSON: https://anlyon.dev/api/v1/servers/io.github.cyanheads/usgs-water-mcp-server
- Version: 0.4.0 (active)
- Publisher: io.github.cyanheads (GitHub account)
- Runs: remote (streamable-http), local (npm)
- Sign-in to list tools: none
- Repository: https://github.com/cyanheads/usgs-water-mcp-server
- Metadata from the official MCP Registry, synced 2026-10-21T18:28:53.733Z

Title and description, as the publisher wrote them:

```untrusted-server-text
Query real-time and historical USGS water data from ~8,000 stream gages and groundwater wells.
```

Scanned 2026-10-21T19:22:44.697Z over streamable-http.

**8 tools: 1 change things and 7 only read.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 1 | ask |
| Only reads | read | 7 | allow |

## Findings

- **warn** Mentions of other tools or servers in `water_list_parameters` ([tool-shadowing](https://anlyon.dev/methodology#tool-shadowing))

```untrusted-server-text
The description contains "every other tool", wording about other tools or servers.

description: "...SGS parameter codes — the 5-digit codes every other tool's parameterCd takes. With no query, lis..."
```

- **warn** Annotations that disagree with the tool in `water_dataframe_query` ([annotation-conflict](https://anlyon.dev/methodology#annotation-conflict))

```untrusted-server-text
The server marks "water_dataframe_query" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The name "water_dataframe_query" says "query": a word for reading.
```


## Changes things (1)

Creates or changes something that can be changed back. Claude Code: ask.

### `water_dataframe_query`

- The name "water_dataframe_query" says "query": a word for reading.
- The description's first verb is "run": a word for a change.
- The input takes a statement or command to run (input.sql), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Findings: warn annotation-conflict

Description, as the server wrote it:

```untrusted-server-text
Run a read-only SQL SELECT against water data tables staged on a DataCanvas by water_get_series or water_find_sites. Workflow: run water_get_series or water_find_sites (get canvas_id + table_name) → water_dataframe_describe (confirm the table and its columns) → water_dataframe_query (SQL analysis), then optionally water_dataframe_drop (when this server enables it) to remove a table you are done with. Only SELECT statements are permitted. At most 10,000 rows are returned; a query matching more is capped and the response sets truncated=true — scope with WHERE/LIMIT, and use SELECT COUNT(*) or water_dataframe_describe to learn the true match count. Requires DataCanvas to be enabled on this server instance. Returns an error if DataCanvas is not available.
```

## Only reads (7)

Looks things up and changes nothing. Claude Code: allow.

### `water_dataframe_describe`

- The name "water_dataframe_describe" says "describe": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
List tables and columns staged on a DataCanvas by water_get_series or water_find_sites. Call this after water_get_series or water_find_sites returns a canvas_id to discover the exact table name and column types before writing a query. Then pass the table name to water_dataframe_query, or to water_dataframe_drop (when this server enables it) to remove a table you no longer need. Requires DataCanvas to be enabled on this server instance. Returns an error if DataCanvas is not available.
```

### `water_find_sites`

- The name "water_find_sites" says "find": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Find USGS water monitoring sites by bounding box, state, county, or HUC watershed code, filtered by site type and parameter availability. Returns site numbers, names, coordinates, types, altitude, and (in expanded mode) drainage area. Call this first — water_get_readings, water_get_series, and water_get_conditions all require a site number. Supply exactly one major filter — bbox, stateCd, countyCd, or huc; siteType, parameterCd, and hasDataTypeCd only narrow within it and cannot stand alone. Page through matches with limit/offset (500 per page); truncated=true means matches remain after the returned window and upstreamTotal holds the full count. When the match set exceeds 500 and DataCanvas is enabled, the complete set also stages to a canvas (canvas_id/table_name) — inspect it with water_dataframe_describe, then retrieve it with water_dataframe_query.
```

### `water_get_conditions`

- The name "water_get_conditions" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Get a USGS site's current reading ranked against its full period-of-record daily-mean percentiles for the same calendar day — a "how unusual is this" percentileClass (record-high to record-low), not a flood-stage or drought determination (this tool fetches no authoritative thresholds). The reading is instantaneous but the percentiles are daily-mean, so the ranking is approximate (see historicalContext.comparisonBasis). When the record is too short to rank, returns the reading with historicalContext=null instead of an error. A reading NWIS reports as no data (a seasonal, discontinued, dry, or malfunctioning gage) returns an empty currentValue with the qualifiers naming why, and is not ranked. When the site measures the parameter with several sensors (methods), one reading is used and named by methodId/methodDescription — from the sensor its percentile series is described as when one is, otherwise the most recent across them; water_get_readings lists every method. Use water_find_sites and water_list_parameters to resolve inputs.
```

### `water_get_readings`

- The name "water_get_readings" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Get the latest instantaneous (~15-min, real-time) values for up to 100 USGS sites in one call — per-site, per-parameter records with timestamp, value, unit, and provisional/approved qualifiers. Omitting parameterCd returns every parameter each site publishes. A site measuring one parameter with several sensors returns one series per method, each named by methodId and methodDescription. At most 100 series return per call — every site that returned data keeps at least one, and totalSeries reports how many NWIS returned; pass parameterCd or split the sites across calls to reach the rest. Each series returns only its 10 most recent records (totalValues reports the true count); truncated=true when either cap applied. Use water_get_series for a full date-range series. Sites NWIS returns nothing for are listed in missingSites, not dropped silently. Use water_find_sites first to discover site numbers and available parameters.
```

### `water_get_series`

- The name "water_get_series" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Get a daily or instantaneous time series for one USGS site and parameter over a date range, as time-ordered value records. NWIS can hold several series for one query — one per daily statistic (mean, maximum, minimum) and one per sensor (method); this returns one, reporting its statCd and methodId, and lists the rest in otherSeries so any can be re-requested with the statCd and methodId inputs. By default it returns the daily mean when NWIS returns one with values, and the method with the most records. Large sets (>500 records) return the most recent records inline with truncated=true — the last 500 without DataCanvas, and with DataCanvas enabled the complete series also spills to a canvas (canvas_id/table_name): inspect the staged table with water_dataframe_describe, then read the full series with water_dataframe_query. Use water_find_sites and water_list_parameters to resolve inputs.
```

### `water_get_site_data_catalog`

- The name "water_get_site_data_catalog" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Discover a USGS site’s parameters, sensors, statistics, and UTC record bounds before calling water_get_series. Find site numbers with water_find_sites. Each row is a distinct series; metadata bounds may contain gaps and lag observations. For water_get_series, take YYYY-MM-DD from beginDate/endDate, pass statCd only for daily rows, and obtain methodId from a water_get_series response; timeSeriesId is an OGC identifier, never an NWIS methodId. Rows with null seriesType are other computations and cannot be requested with water_get_series. Follow nextCursor with the same filters and limit until null.
```

### `water_list_parameters`

- The name "water_list_parameters" says "list": a word for reading.
- Findings: warn tool-shadowing

Description, as the server wrote it:

```untrusted-server-text
Look up USGS parameter codes — the 5-digit codes every other tool's parameterCd takes. With no query, lists a curated set of well-known codes with names, units, and thematic group, from a built-in table (no network call): 00060 = "Discharge" (ft³/s), 00065 = "Gage height" (ft), 00010 = "Temperature, water" (°C), 72019 = "Depth to water level" (ft), and others; filter it with group. For anything else — turbidity, nitrate, chlorophyll, suspended sediment, salinity — pass query to search the full USGS parameter-code catalog (~19,600 codes) by name and description, or pass a 5-digit code to look it up. A query returns at most 25 entries, matching curated codes first, with total counting every match.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `usgs-water`:

```json
{
  "permissions": {
    "allow": [
      "mcp__usgs-water__water_list_parameters",
      "mcp__usgs-water__water_find_sites",
      "mcp__usgs-water__water_get_readings",
      "mcp__usgs-water__water_get_series",
      "mcp__usgs-water__water_get_site_data_catalog",
      "mcp__usgs-water__water_get_conditions",
      "mcp__usgs-water__water_dataframe_describe"
    ],
    "ask": [
      "mcp__usgs-water__water_dataframe_query"
    ],
    "deny": []
  }
}
```