DC Hub

Compare ISO Regions

compare_isos

Read-onlyIdempotent

Use this whenever the user asks to compare two to four US grids side by side. Use when a user wants a side-by-side of 2-4 ISO grids — fuel mix, demand, renewable/gas share, interconnection-queue depth, time-to-power — in one call instead of N sequential get_grid_intelligence calls. Example: "Compare PJM vs ERCOT vs CAISO on gas share, renewable share, and queue depth right now." — compare_isos isos="PJM,ERCOT,CAISO". Params: isos is a comma-separated list (2-4 max) drawn from the 7 live US ISOs: "PJM" | "ERCOT" | "CAISO" | "MISO" | "SPP" | "NYISO" | "ISO-NE". Returns: {isos[], comparison:{:{demand_mw, generation_mix_pct, renewable_share_pct, gas_share_pct, constraint_score, excess_power_score, avg_time_to_power_months, avg_queue_wait_months, queue_depth_gw, retail_price_cents_kwh}}, as_of}. ★avg_time_to_power_months (DCPI per-market estimate, ISO-averaged) and avg_queue_wait_months (proxy from live queue DEPTH) are DIFFERENT measurements — quote whichever you mean by name. Do NOT use to rank ALL grids globally (use get_grid_scoreboard) or for the single-ISO deep brief (use get_grid_intelligence).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`isos`	Yes	Comma-separated list of 2-4 US ISO/RTO grid regions to compare, e.g. "PJM,ERCOT,CAISO" (valid: ERCOT, PJM, MISO, CAISO, SPP, NYISO, ISONE)

Output Schema

TableJSON Schema

Name	Required	Description
`quota`	No	Caller quota state (remaining calls, tier).
`_entity`	No	Payload class (facility\|market\|iso_grid\|queue_results\|deal\|report\|response); branch on it.
`citation`	No	How to attribute DC Hub: {source, url, license, cite_as, retrieved_at}, or the attribution line as a string.
`provenance`	No	Source, method, as_of, verification_counts, license, cite_as; quote it when citing.
`_front_door`	No	First-tool hint: plan_query(intent) returns the ordered plan.
`_return_loop`	No	Next-session delta call (get_changes).
`site_evaluation_handoff`	No	Follow-up calls [{tool, parameters, why}] when the payload carries coordinates.

Schema Changelog

Changes observed during successful MCP inspections.

AddedOct 9, 2026
RemovedSep 29, 2026
Changed1 schema field changedAug 29, 2026
- addedInput schema / required
```
Added value: +[
+  "isos"
+]
```

Changed2 schema fields changedAug 21, 2026

removedInput schema / $schema

Removed value: -"http://json-schema.org/draft-07/schema#"

removedOutput schema / $schema

Removed value: -"http://json-schema.org/draft-07/schema#"

Changed5 schema fields changedAug 11, 2026

removedOutput schema / properties / citation / additionalProperties
```
Removed value: -{}
```

addedOutput schema / properties / citation / anyOf

Added value: +[
+  {
+    "additionalProperties": {},
+    "properties": {},
+    "type": "object"
+  },
+  {
+    "type": "string"
+  }
+]

changedOutput schema / properties / citation / description

Previous value: -"Machine-readable citation: how to attribute DC Hub (dchub.cloud) for this payload."New value: +"Machine-readable citation: how to attribute DC Hub (dchub.cloud) for this payload. Normally an OBJECT {source, url, license, cite_as, retrieved_at}; a bare string is accepted and carries the attribution line itself."

removedOutput schema / properties / citation / properties
```
Removed value: -{}
```
removedOutput schema / properties / citation / type
```
Removed value: -"object"
```

Changed1 schema field changedJul 21, 2026

addedOutput schema / properties / _front_door

Added value: +{
+  "additionalProperties": {},
+  "description": "In-band front-door hint (first workflow-entry tool of a session): call plan_query(intent) first for the ordered multi-step plan.",
+  "properties": {},
+  "type": "object"
+}

Changed5 schema fields changedJul 18, 2026

removedOutput schema / properties / site_evaluation_handoff / additionalProperties
```
Removed value: -{}
```

addedOutput schema / properties / site_evaluation_handoff / anyOf

Added value: +[
+  {
+    "items": {
+      "additionalProperties": {},
+      "properties": {},
+      "type": "object"
+    },
+    "type": "array"
+  },
+  {
+    "additionalProperties": {},
+    "properties": {},
+    "type": "object"
+  }
+]

changedOutput schema / properties / site_evaluation_handoff / description

Previous value: -"Pre-built follow-up call (analyze_site / get_water_risk args) when the payload carries coordinates."New value: +"Pre-built follow-up calls (analyze_site / get_water_risk args) when the payload carries coordinates — an array of {tool, parameters, why} entries."

removedOutput schema / properties / site_evaluation_handoff / properties
```
Removed value: -{}
```
removedOutput schema / properties / site_evaluation_handoff / type
```
Removed value: -"object"
```

Changed1 schema field changedJul 17, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": {},
+  "description": "DC Hub envelope: structuredContent mirrors the JSON payload in content[0].text — tool-specific data fields ride at the top level alongside these envelope keys.",
+  "properties": {
+    "_entity": {
+      "description": "Payload class discriminator (e.g. facility|market|iso_grid|queue_results|deal|report|response) — branch on this before parsing the rest.",
+      "type": "string"
+    },
+    "_return_loop": {
+      "additionalProperties": {},
+      "description": "Suggested next-session delta call (get_changes since=24h) so you pull only what changed.",
+      "properties": {},
+      "type": "object"
+    },
+    "citation": {
+      "additionalProperties": {},
+      "description": "Machine-readable citation: how to attribute DC Hub (dchub.cloud) for this payload.",
+      "properties": {},
+      "type": "object"
+    },
+    "provenance": {
+      "additionalProperties": {},
+      "description": "Collection-level provenance block: {source, method, as_of, verification_counts, cite_url_template, license, cite_as}. Quote the verification level when citing.",
+      "properties": {},
+      "type": "object"
+    },
+    "quota": {
+      "additionalProperties": {},
+      "description": "Caller quota state (remaining calls, tier) when available.",
+      "properties": {},
+      "type": "object"
+    },
+    "site_evaluation_handoff": {
+      "additionalProperties": {},
+      "description": "Pre-built follow-up call (analyze_site / get_water_risk args) when the payload carries coordinates.",
+      "properties": {},
+      "type": "object"
+    }
+  },
+  "type": "object"
+}

Changed1 schema field changedJul 2, 2026

addedInput schema / properties / isos / description

Added value: +"Comma-separated list of 2-4 US ISO/RTO grid regions to compare, e.g. \"PJM,ERCOT,CAISO\" (valid: ERCOT, PJM, MISO, CAISO, SPP, NYISO, ISONE)"

AddedMay 25, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already declare readOnly, idempotent, non-destructive, openWorld, so the safety profile is covered. The description adds real value beyond that: it caps input at 2-4, sketches the returned comparison shape, and warns that avg_time_to_power_months and avg_queue_wait_months are DIFFERENT measurements that must be quoted by name. It does not add operational constraints like rate limits or auth, so a 4 rather than a 5.

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 usage trigger, then example, params, returns, and exclusions in a logical order. Slightly verbose: the opening two sentences both restate the 2-4 side-by-side comparison, and the full return-key list is largely redundant given an output schema exists.

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 a single required parameter, full schema coverage, and an output schema, the description supplies everything an agent needs: when to use, when not to, the alternative tools, input bounds, and a meaningful caveat about two similar-sounding metrics. Nothing required for a correct call 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 coverage is 100%, so the schema already documents the single 'isos' parameter, its 2-4 range, example, and valid set — this is the baseline-3 case. The description reinforces the same facts but adds no new syntax. It also introduces a value mismatch worth noting: the description lists 'ISO-NE' while the schema enumerates 'ISONE'.

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 ('compare') and resource ('2-4 US ISO grids side by side'), names the compared dimensions (fuel mix, demand, renewable/gas share, queue depth, time-to-power), and explicitly names the siblings it is NOT (get_grid_scoreboard, get_grid_intelligence). An agent can distinguish it without opening any schema.

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?

Gives an explicit trigger ('whenever the user asks to compare two to four US grids side by side'), a concrete example invocation, and explicit exclusions routing to the correct alternatives ('Do NOT use to rank ALL grids globally — use get_grid_scoreboard' and 'for the single-ISO deep brief — use get_grid_intelligence'). Nothing is left to inference.

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

All DC Hub 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.