Passage Data — cited environmental limits

Check a value against cited limits

check_value

Read-onlyIdempotent

Is a measured value over the limits we hold? Give a parameter, a number and its unit (and a place, medium or statistic to narrow). Every row find_limits would return comes back with a verdict: over, within, under (below a floor or a band's bottom), or not_comparable with a why (a unit of another family or one we never convert, a number that depends on the water's hardness, pH or temperature, an equation or narrative, a value printed for reference, a row under a longer parameter name). Units convert exactly within a family (µg/L to mg/L); no limit is summed or inferred. counts totals the verdicts over all rows. Quote each row's cite; whether its statistic and conditions are yours is for you to say.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "parameter": "<parameter>",
      "value": "<value>",
      "unit": "<unit>"
    },
    "name": "check_value"
  }
}

Input Schema

Name	Required	Description
`unit`	Yes	The value's unit: mg/L, µg/L (or ug/L, mg L-1), ng/L, mg/kg, µg/m³, pH (or SU) ...
`place`	No	ISO 3166 code of where the rule binds: a country (US, CA, DE, FR, IT), a state or province (US-OH, CA-QC), or EU. A place also searches every place above it: US-OH searches US-OH and US; DE searches DE and EU. Omit to search everywhere.
`value`	Yes	The measured value, one number (0.15). A decimal string is read too, with a point or one decimal comma (0,15); 1,500 is refused as ambiguous.
`medium`	No	What the limit governs: an effluent (water_discharge), the receiving water (surface_water), groundwater, air.
`offset`	No	Where the next page starts (the answer's next_offset); rows come over first, then under, within, not_comparable.
`max_rows`	No
`parameter`	Yes	The substance or measure as a regulation names it (copper, ammonia, pH) or its CAS number.
`statistic`	No	Only rows under this statistic: daily_max, monthly_avg, instant, composite, ...

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedOct 14, 2026

changedInput schema / properties / unit / description

Previous value: -"The value's unit: mg/L, µg/L (or ug/L), ng/L, mg/kg, µg/m³, pH ..."New value: +"The value's unit: mg/L, µg/L (or ug/L, mg L-1), ng/L, mg/kg, µg/m³, pH (or SU) ..."

changedInput schema / properties / value / description

Previous value: -"The measured value, one number (0.15). A decimal string is read too."New value: +"The measured value, one number (0.15). A decimal string is read too, with a point or one decimal comma (0,15); 1,500 is refused as ambiguous."

Changed1 schema field changedOct 14, 2026

changedInput schema / properties / medium / enum

Previous value: -[
-  "water_discharge",
-  "surface_water",
-  "groundwater",
-  "ambient_air",
-  "air_emission",
-  "sediment",
-  "leachate"
-]New value: +[
+  "water_discharge",
+  "surface_water",
+  "groundwater",
+  "drinking_water",
+  "soil",
+  "ambient_air",
+  "air_emission",
+  "sediment",
+  "leachate"
+]

First observedOct 14, 2026

TDQS

A4.4/5.0

Behavior5/5

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

Beyond the read-only/idempotent annotations, it enumerates the exact verdict vocabulary (over, within, under, not_comparable) and the reasons a row is not comparable, states that units convert exactly within a family, that no limit is summed or inferred, and that counts totals verdicts. This is unusually rich behavioral disclosure for a read tool.

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

Conciseness4/5

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

The core question is front-loaded in the first clause, followed by input requirements and then return semantics. It is dense and parenthetical-heavy, but nearly every clause carries distinct information with little 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?

With no output schema, the description carries the return-value burden and does so: per-row verdicts, the not_comparable `why`, `counts` totals, the `cite` field, and pagination ordering. For an 8-parameter read tool with strong annotations, nothing an agent needs to call and interpret it is missing.

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

Parameters3/5

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

Schema description coverage is 88%, so the schema already documents unit, place, value, offset, statistic and medium in detail. The description largely restates the same inputs (parameter/number/unit) and adds only incidental value such as the µg/L-to-mg/L conversion note and the cite-quoting reminder, so the baseline 3 applies.

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?

States a specific verb and resource ('Is a measured value over the limits we hold?'), and explicitly anchors itself against a sibling by describing its output as 'every row find_limits would return ... with a verdict.' An agent can distinguish it from check_values and find_limits without opening a schema.

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

Usage Guidelines4/5

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

Gives clear input requirements ('give a parameter, a number and its unit (and a place, medium or statistic to narrow)') and implies the decision rule via its relationship to find_limits. It stops short of an explicit 'use find_limits instead when you only need the limits' exclusion, so it is clear context rather than full when/when-not guidance.

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

All Passage Data — cited environmental limits tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.