ICOS carbon and greenhouse-gas observations

aggregate

Read-onlyIdempotent

Statistics over a WHOLE selection, computed on the server: count, mean, min, max, sum and standard deviation of one variable, overall or per station, year, month or day. Use this for any average, total, range or trend instead of reading rows. Any size: a selection over 500,000 rows is split by time on the server and merged exactly. std is the POPULATION standard deviation (ddof 0). sum adds the values as stored, which is a total only for values that are themselves totals per row: summing a RATE (umol m-2 s-1 per half-hour, gC m-2 d-1 per day) or a concentration gives no physical quantity -- for a flux total multiply the mean by the period.

Input Schema

Name	Required	Description	Default
`by`	No	the groups: none (one result), station, a period, or both	none
`id`	Yes	a variable id from search_variables
`end`	No	ISO date or datetime, EXCLUSIVE
`start`	No	ISO date or datetime, inclusive (2025-01-01)
`cruise`	No	cruise expocodes, a list or a string; ocean observation tables only
`lat_max`	No
`lat_min`	No
`lon_max`	No
`lon_min`	No
`station`	No	station ids -- a list, or one id (or several, comma-separated) as a string; CASE-SENSITIVE: HTM150 (trigram + sampling height) for atmosphere, SE-Htm for FLUXNET sites
`apply_qc`	No	DEFAULT TRUE: drop the observations the store's recommended quality control rejects; false keeps every observation, flagged ones included
`height_max`	No
`height_min`	No

Output Schema

Name	Required	Description
`by`	Yes
`id`	Yes
`note`	No
`unit`	No
`groups`	Yes	one entry per group: its keys (station, period), n (finite values), and mean, min, max, sum, std over them (null when n is 0)
`citation`	Yes
`n_groups`	Yes
`variable`	Yes
`rows_used`	Yes
`download_url`	Yes
`download_urls`	No
`download_complete`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 30, 2026

TDQS

A4.3/5.0

Behavior5/5

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

With readOnly/idempotent annotations already covering safety, the description adds real semantics: server-side chunking and exact merge for selections over 500,000 rows, population std (ddof 0), and the crucial caveat that summing a rate or concentration yields no physical quantity. This is context an agent cannot get from annotations or schema.

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?

Front-loaded with the capability and the 'instead of reading rows' guidance, followed by scale guarantees and statistical caveats. The rate-summation passage is long but each sentence carries non-obvious information; little waste.

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

Completeness4/5

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

Output schema exists, so return values need not be explained, and the statistical semantics and exactness guarantees are covered. The remaining gap is the spatial and height filter parameters, which are neither described here nor in the schema.

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 coverage is only 54% across 13 parameters, so the description should compensate more. It echoes the grouping enum values (station, year, month, day) and implies the variable id, but says nothing about lat/lon, height, or cruise filters, which are undocumented in the schema as well.

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+resource: server-side statistics (count, mean, min, max, sum, std) over a whole selection of one variable, with grouping options named explicitly. It is clearly separable from siblings like get_data (row reading) and estimate.

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?

Explicitly instructs 'Use this for any average, total, range or trend instead of reading rows', naming the alternative behavior to avoid. It lacks a named sibling or an explicit when-not condition, but the steering is strong and includes the flux-total workaround.

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

All ICOS carbon and greenhouse-gas observations 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.

Resources

Need Help?