Skip to main content
Glama

NOAA Tides and Currents

by io.github.RyanCardin15
OverviewAdmin

Get Tide Predictions

noaa_get_tide_predictions
Read-onlyIdempotent

Get NOAA harmonic tide predictions (future or past) for a station.

interval="hilo" (recommended for "when is high/low tide") returns the daily tide events with type H/L — up to 10 years per request. Other intervals (h, 1, 5, 6, 10, 15, 30, 60 minutes) return a height time series — up to 1 year per request.

Heights are relative to the requested datum (MLLW default). Notes:

  • Great Lakes stations have NO tide predictions (lake levels are not tidal).

  • Subordinate stations (type "S") only support interval=hilo; use the station's reference (R) station for interval series.

  • Predictions are astronomical only — they exclude weather effects (storm surge, wind setup). Compare with noaa_get_water_levels for actual conditions.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
dateNoShortcut window: "today" = midnight to now, "latest" = single most recent reading, "recent" = last 72 hours. Mutually exclusive with begin_date/end_date/range.
datumNoVertical reference datum for heights. MLLW is the standard chart datum for coastal stations. IGLD and LWD apply to Great Lakes stations ONLY; NAVD/CRD exist only at stations where computed. Check a station's supported datums with noaa_get_station_datums.MLLW
rangeNoNumber of hours. With begin_date: hours forward. With end_date: hours back. Alone: hours back from now.
unitsNoUnit system. english: feet, °F, knots (wind AND currents), nautical miles. metric: meters, °C, m/s for wind but cm/s for currents, kilometers. Air pressure is millibars and salinity is PSU in BOTH systems.english
stationYesStation ID. Water-level/met stations use 7-digit numeric IDs (e.g. "9414290" San Francisco); current stations use alphanumeric IDs (e.g. "cb0102"). Find stations with noaa_search_stations or noaa_find_nearest_stations.
end_dateNoEnd date/time. Same formats as begin_date.
intervalNo"hilo" = high/low tide events only (max 10-year span). "h" = hourly, or 1/5/6/10/15/30/60-minute series (max 1-year span).hilo
time_zoneNoTime zone for timestamps: gmt = UTC, lst = station local standard time (no DST), lst_ldt = station local time with DST. Note: daily_mean data requires lst.lst_ldt
begin_dateNoStart date/time. Formats: yyyyMMdd, "yyyyMMdd HH:mm", MM/dd/yyyy, or ISO yyyy-MM-dd[THH:mm].
response_formatNoOutput format: "markdown" for a readable summary table, "json" for the complete structured payload.markdown

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. First observed

TDQS

A4.9/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond annotations (readOnly, idempotent, etc.), the description adds critical behavioral details: max time spans (10 years for hilo, 1 year for others), datum relativity, limitations for specific station types, and exclusion of weather effects. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: opening sentence with core purpose, bullet points for key notes, and logical flow. Every sentence adds value without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (10 params, 1 required, many siblings), the description covers all necessary aspects: purpose, usage guidance, behavioral constraints, parameter context, and cross-references to related tools. No output schema needed as response_format parameter is documented.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so parameters are already documented. The description adds value by explaining the behavior of interval types and constraints on usage (e.g., subordinate stations only support hilo). This goes beyond simple parameter listing, earning a 4.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool fetches NOAA harmonic tide predictions for a station, distinguishes between interval types (hilo for high/low events vs. time series), and notes limitations (Great Lakes, subordinate stations, astronomical only). This differentiation from siblings like noaa_get_water_levels is explicit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit usage guidance: recommends hilo for tide event queries, notes max time spans per interval, cautions about Great Lakes and subordinate stations, and suggests comparing with noaa_get_water_levels for actual conditions. This helps the agent decide when to use this tool vs. alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All NOAA Tides and Currents toolsInspect
Try in Browser
RayrunBuild, deploy, and operate MCP servers without becoming an infrastructure team.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources