Periodic Table Grounding Data
The tool
Ground agents in verifiable element data — atomic number, mass, electron configuration — so chemistry answers rest on real reference values.
Once your client is connected to the VerveContext MCP server, this appears in its tool list as PeriodicTableGroundingData. It is read-only and open-world: it fetches, it never mutates anything on your side, so most clients will call it without asking you to confirm.
{
"name": "PeriodicTableGroundingData",
"arguments": {
"name": "hydrogen"
}
}What that looks like in a conversation
You don't name the tool — the model picks it. Asking about hydrogen in the terms this source covers is enough for it to reach for PeriodicTableGroundingData on its own.
Connecting
One server URL covers every source in the catalog, including this one. Authorization is OAuth — the client opens a browser once and there is no key to paste into a config file.
{
"mcpServers": {
"vervecontext": {
"url": "https://api.vervecontext.com/v1/mcp"
}
}
}https://api.vervecontext.com/v1/mcpPer-client setup — Claude Desktop, Cursor, VS Code, ChatGPT — is on the MCP setup page.
Arguments
These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made.
| Argument | Type | Example | Description |
|---|---|---|---|
nameRequired | string | hydrogen | The name of the chemical element to get information about |
What the model gets back
The result carries a structuredContent object matching the tool's declared outputSchema, so a client can read fields without parsing prose. status is "ok" on success and error is null; a null field means the value wasn't available for that input, not that the call failed.
{
"status": "ok",
"error": null,
"data": {
"count": 1,
"elements": [
{
"name": "Hydrogen",
"appearance": "colorless gas",
"atomic_mass": 1.008,
"boil": 20.271,
"category": "diatomic nonmetal",
"density": 0.08988,
"discovered_by": "Henry Cavendish",
"melt": 13.99,
"molar_heat": 28.836,
"named_by": "Antoine Lavoisier",
"number": 1,
"period": 1,
"group": 1,
"phase": "Gas",
"source": "https://en.wikipedia.org/wiki/Hydrogen",
"summary": "Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.",
"symbol": "H",
"xpos": 1,
"ypos": 1,
"wxpos": 1,
"wypos": 1,
"shells": [
1
],
"electron_configuration": "1s1",
"electron_configuration_semantic": "1s1",
"electron_affinity": 72.769,
"electronegativity_pauling": 2.2,
"ionization_energies": [
1312
],
"cpk-hex": "ffffff",
"block": "s"
}
]
}
}Fields
| Field | Type | Example | Description |
|---|---|---|---|
count | number | ||
elements | array[1] | ||
└ elements.0.name | string | Chemical element name | |
└ elements.0.appearance | string | Physical appearance of the element | |
└ elements.0.atomic_massPremium | number | Atomic mass of the element | |
└ elements.0.boilPremium | number | Boiling point temperature in Kelvin | |
└ elements.0.category | string | Classification category of element | |
└ elements.0.densityPremium | number | Element density at standard conditions | |
└ elements.0.discovered_by | string | Name of element discoverer | |
└ elements.0.meltPremium | number | Melting point temperature in Kelvin | |
└ elements.0.molar_heatPremium | number | Molar heat capacity value | |
└ elements.0.named_by | string | Person who named the element | |
└ elements.0.number | number | Atomic number of the element | |
└ elements.0.period | number | Period position in periodic table | |
└ elements.0.group | number | Group position in periodic table | |
└ elements.0.phase | string | Physical state of element at standard conditions | |
└ elements.0.source | string | URL reference source for element info | |
└ elements.0.summaryPremium | string | Detailed summary about the element | |
└ elements.0.symbol | string | Chemical symbol for the element | |
└ elements.0.xpos | number | X position coordinate in periodic table | |
└ elements.0.ypos | number | Y position coordinate in periodic table | |
└ elements.0.wxpos | number | Width X position in periodic table layout | |
└ elements.0.wypos | number | Width Y position in periodic table layout | |
└ elements.0.shellsPremium | array | Array of electron shell configurations | |
└ elements.0.electron_configurationPremium | string | Full electron configuration notation | |
└ elements.0.electron_configuration_semanticPremium | string | Semantic electron configuration notation | |
└ elements.0.electron_affinityPremium | number | Electron affinity in kJ/mol | |
└ elements.0.electronegativity_paulingPremium | number | Electronegativity on Pauling scale | |
└ elements.0.ionization_energiesPremium | array | Array of ionization energy values | |
└ elements.0.cpk-hex | string | CPK color hex code for element | |
└ elements.0.block | string | Block designation in periodic table |
Why ground on it
A model can produce something that looks like this answer from its training data, and be confidently out of date or simply wrong. This source returns the current value with a shape you can check, which is the difference between an answer you can cite and one you have to hedge.
Point an evaluation at count: it is the field most worth pinning a claim to, and it is either present and current or absent — never plausibly invented.
Failure modes
Errors come back as tool errors with a sentence the model can act on, not a bare status code.
| Status | What it means |
|---|---|
400 / 422 | The arguments didn't validate. The message names the offending one. |
401 | The OAuth session is invalid or expired — reconnect the server. |
403 | Out of credits. Not a bad key — the month's allowance is spent. |
404 | This source isn't part of VerveContext. Check the catalog. |
429 | Brief rate limit. Retrying after a moment succeeds. |
Other ways to use Periodic Table Grounding Data
Set up Periodic Table Grounding Data on VerveContext, or reach the same source a different way. Your VerveContext account and credits work on all of them — one key, one balance.
Frequently asked questions
Do I have to tell the agent to use PeriodicTableGroundingData?
No. The tool's name and description are in the model's context once the server is connected, so it selects the tool when the question calls for it. Naming it explicitly works too and is useful when you want to force the call.
Does connecting the server expose every tool at once?
Yes — one connection lists the whole VerveContext catalog. Clients with a tool budget can usually filter the list; the credit cost is per call, so an unused tool costs nothing.
What does a call cost?
1 credit each time the tool actually runs. A model that reasons about the tool without calling it costs nothing.
Is there a REST version of this?
Yes — the same source is available as a plain HTTPS endpoint on APIVerve, linked above. Same data, same credits, same account.