Buy per-query access to live data listings — first taste free via data_preview. Listing: hnfrontpage: Hacker News Front Page (Live) (0.01 USDC/query (max 20 queries/session)). Open a prepaid session, then fund and query.
| Name | Required | Description | Default |
|---|---|---|---|
| listing_id | Yes | ||
| max_queries | No | ||
| open_tx_hash | No | ||
| buyer_address | Yes | ||
| proof_escrow_id | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations provide readOnlyHint=false and idempotentHint=false, indicating this is a mutating operation. The description adds valuable behavioral context: the session is prepaid, costs 0.01 USDC/query, and is capped at 20 queries per session. This clarifies the financial and session-bound behavior beyond the raw annotation flags.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is compact and front-loads the core action. The listing-specific pricing detail is somewhat tangential and could belong in schema metadata, but the overall structure is efficient and readable.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema and zero parameter descriptions, this paid, multi-step session-opening tool needs more guidance. The description omits critical context around payment mechanics, optional transaction hashes, escrow IDs, and what a successful open returns. It is not complete enough for an agent to invoke confidently without external knowledge.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate, but it does not explain the required buyer_address or the optional open_tx_hash, max_queries, and proof_escrow_id parameters. It only references a specific listing and pricing, which is not enough to correctly fill the parameters.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's purpose: buying per-query access to live data listings and opening a prepaid session. It names a concrete listing and distinguishes itself from data_preview, making the operation identifiable.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It explicitly suggests using data_preview first as a free taste and lays out a workflow: open a prepaid session, then fund and query. It does not explicitly enumerate when to choose data_session_attach_escrow or data_session_fund, but the sequencing gives usable guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Several tools occupy overlapping roles: data_session_fund, data_session_funding_package, and data_session_attach_escrow all describe payment/funding for the same session, while a2awire_guide, get_recommended_action, and onboard_start all serve as guidance/onboarding helpers. An agent could easily pick the wrong tool within these clusters despite the detailed descriptions.
Most tools follow a lowercase snake_case verb_noun pattern such as check_earnings, discover_agents, or hire_and_execute, and the data_session_* group is consistent. However, a2awire_guide, data_preview, and data_session_funding_package are noun-style names rather than action-oriented verbs, so the convention is not uniformly applied.
Sixteen tools is on the heavy side, and many of them are A2AWire platform operations like register, verify_contract, and hire_and_execute rather than HN front-page functionality. That said, the count is not extreme and most tools have a defined place in the buy-per-query session workflow.
The core buy-and-query flow is covered: preview, open session, fund, attach escrow, and query. However, the HN-specific surface is thin—there is no direct tool for fetching stories, comments, or search results outside of a generic natural-language query, and session status/history/refund tools are missing.