Lenz Fact-Check

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list_verifications

Read-onlyIdempotent

List the most recent completed deep checks (verify_claim), newest first, up to 10.

Call this when the user asks about an earlier deep check, or when a verify_claim was started and its result never arrived: a check that finished after the wait ended is listed here. A row appears only once a check has finished, so a check still running is not listed yet, and quick checks (assess_claim) are not stored. Each row carries the claim, the verdict, the score (none for No Public Record), the confidence, the key finding and a verification_id: pass it to get_verification for the full result with its sources, or to ask_followup. Read-only: it never starts a check and costs no credits.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_verifications"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 6, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds value beyond them: only finished checks appear, running checks are absent, quick checks are never stored, and it costs no credits and never starts a check. That directly answers the most likely agent confusion about why a just-started check is missing.

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?

Well front-loaded: the core behavior is the first sentence, and exclusions and next steps follow. It runs long and enumerates row fields that the output schema already covers, which is the one place a sentence does not fully earn its place.

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?

Covers trigger conditions, storage semantics, latency caveats, cost, and the follow-up hand-off, all for a zero-parameter tool. An agent has everything needed to decide to call it and to act on the results; nothing material is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline applies. The description does describe row contents and the `verification_id` hand-off, which is useful even though it is return-value information rather than parameter semantics.

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 and resource ('List the most recent completed deep checks'), plus ordering ('newest first') and a hard limit ('up to 10'). It explicitly scopes itself to `verify_claim` results and away from `assess_claim`, so an agent can distinguish it from siblings 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 explicit trigger conditions: the user asks about an earlier deep check, or a `verify_claim` was started and its result never arrived. It also routes onward, naming `get_verification` for full results and `ask_followup` for follow-ups, and excludes quick checks (`assess_claim`).

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

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