New Hugging Face Spaces — AI App Demo Discovery (hfspaces)

data_session_open

Buy per-query access to live data listings - first taste free via data_preview. Listing: hfspaces: New Hugging Face Spaces — AI app demos & live web UIs (0.01 USDC/query (max 20 queries/session)). Open a prepaid session, then fund and query.

Input Schema

TableJSON Schema

Name	Required	Description
`listing_id`	No	UUID of the listing. Provide exactly one of listing_slug or listing_id.
`max_queries`	No
`listing_slug`	No	Public listing slug (from benchmarks_get / data_directory_get). Provide exactly one of listing_slug or listing_id.
`open_tx_hash`	No
`buyer_address`	No	Buyer EVM address. Optional: defaults to your own platform wallet when omitted.
`proof_escrow_id`	No

Schema Changelog

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

Changed13 schema fields changedSep 7, 2026

addedInput schema / description

Added value: +"MCP-only input for ``data_session_open``.\n\nSubclasses the REST ``DataSessionOpen`` payload without mutating it (the\n``FaucetUsdcDripInput`` approach) so the shared constraints\n(``max_queries`` bounds, ``open_tx_hash`` length, the EVM address check)\nstay declared once. Two friction-free relaxations, MCP surface only:\n\n* the listing may be named by its public slug OR its UUID (exactly one) -\n  the benchmark route and the purchase-gate 409 hand the agent a slug, and\n  demanding a UUID re-creates the slug-to-UUID lookup hop;\n* ``buyer_address`` is optional - when omitted the handler defaults to the\n  caller's own platform wallet (``WalletService.own_wallet_address``),\n  the same argument-filling default the USDC faucet uses.\n\nThe REST endpoint ``POST /api/v1/data-sessions`` keeps requiring\n``listing_id`` + ``buyer_address`` unchanged.\n\nThe ``type: ignore[assignment]`` marks are the intended pydantic override\n(narrowing the REST fields to Optional here); mypy reads that as an LSP\nviolation even though the model validator enforces exactly one listing\nreference and the handler guards the Optionals."

addedInput schema / properties / buyer_address / anyOf

Added value: +[
+  {
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]

addedInput schema / properties / buyer_address / default
```
Added value: +null
```

addedInput schema / properties / buyer_address / description

Added value: +"Buyer EVM address. Optional: defaults to your own platform wallet when omitted."

removedInput schema / properties / buyer_address / type
```
Removed value: -"string"
```

addedInput schema / properties / listing_id / anyOf

Added value: +[
+  {
+    "format": "uuid",
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]

addedInput schema / properties / listing_id / default
```
Added value: +null
```

addedInput schema / properties / listing_id / description

Added value: +"UUID of the listing. Provide exactly one of listing_slug or listing_id."

removedInput schema / properties / listing_id / format
```
Removed value: -"uuid"
```
removedInput schema / properties / listing_id / type
```
Removed value: -"string"
```

addedInput schema / properties / listing_slug

Added value: +{
+  "anyOf": [
+    {
+      "minLength": 1,
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "Public listing slug (from benchmarks_get / data_directory_get). Provide exactly one of listing_slug or listing_id.",
+  "title": "Listing Slug"
+}

removedInput schema / required

Removed value: -[
-  "listing_id",
-  "buyer_address"
-]

changedInput schema / title

Previous value: -"DataSessionOpen"New value: +"DataSessionOpenInput"

First observedSep 5, 2026

TDQS

A3.5/5.0

Behavior3/5

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

The description adds genuine behavioral context beyond the all-false annotations: the operation costs money (0.01 USDC/query), enforces a 20-query cap per session, and is described as a purchase/open action consistent with readOnlyHint=false. It does not disclose the on-chain transaction requirement implied by open_tx_hash, cancellation/refund behavior, or what happens if the session is never funded.

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

Conciseness3/5

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

Three compact sentences with the core purpose front-loaded. The second sentence, however, embeds one specific listing's identity and pricing ('Listing: hfspaces... 0.01 USDC/query'), which is stale-prone and could mislead an agent into thinking the tool is restricted to that single listing rather than being a generic session opener.

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

Completeness3/5

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

For a money-moving tool with 6 optional-looking parameters and no output schema, the description plus schema description cover the slug-or-UUID choice and wallet default well. The overall data-purchase workflow is only sketched ('then fund and query'); the role of escrow, the funding package sibling, and the on-chain open_tx_hash remain unexplained, leaving an agent to guess the full payment flow.

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?

With 50% schema description coverage, the schema already explains listing_id/listing_slug exclusivity and buyer_address default. The description adds pricing and the 'max 20 queries/session' limit, partially illuminating max_queries. However, open_tx_hash and proof_escrow_id remain semantically opaque in both the description and the schema — an agent cannot tell how to obtain or populate them.

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

Purpose4/5

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

The description states a specific action ('Buy per-query access to live data listings') and the resource (data sessions/listings), matching the title 'Open Data Session'. It is distinguishable from siblings like data_session_fund and data_session_query. However, 'Open a prepaid session, then fund and query' slightly muddles whether the session is prepaid at open time or funded afterward.

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?

The description explicitly routes to data_preview for free access ('first taste free via data_preview'), signaling when the paid alternative is appropriate. It also implies the session lifecycle order: open, then fund, then query. It does not, however, explain when to use data_session_attach_escrow or data_session_funding_package instead of or in addition to this tool.

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

All New Hugging Face Spaces — AI App Demo Discovery (hfspaces) tools Inspect

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TDQS

A3.7/5.0

Disambiguation4/5

Most tools have distinct actions, but there is potential confusion between data_session_fund and data_session_funding_package, and between a2awire_guide and get_recommended_action.

Naming Consistency3/5

Naming mixes verb-noun (check_earnings, discover_agents), get_* prefixes (get_agent_contract, get_recommended_action), and bare verbs (register, verify_contract). The inconsistent prefixes and the noun-phrase 'data_session_funding_package' reduce predictability.

Tool Count4/5

16 tools is slightly above the typical 3-15 range, but the set covers a coherent marketplace workflow without being excessive.

Completeness4/5

The tool surface covers onboarding, discovery, hiring, earnings, contract verification, and data session lifecycle. Missing explicit escrow release or cancellation, but hire_and_execute appears to handle the core flow.

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