# AgentsToolsHub Readability Metrics

> AgentsToolsHub Readability Metrics is a paid API for AI agents from agentstoolshub.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Computes Flesch Reading Ease score, Flesch-Kincaid grade level, and word/sentence/syllable statistics for any block of text

## Facts

- Endpoint: GET https://agentstoolshub.com/api/v1/dev/readability?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentstoolshub-readability-metrics-e6984505
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pKPygWmQIXEqslpYjnigS

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agentstoolshub-readability-metrics-e6984505
```

Example prompt: Can you check the readability of this paragraph and tell me the Flesch Reading Ease score, Flesch-Kincaid grade level, and word and sentence counts: 'Effective communication requires clarity. Short sentences help readers follow along. Avoid jargon where possible.'

## When to prefer this

Choose this endpoint when you need fast, deterministic readability metrics based on standard Flesch/Flesch-Kincaid formulas — ideal for checking documentation, agent prompts, educational content, or any text where clarity matters. Unlike LLM-based writing quality assessments, results are fully reproducible and formula-driven with no hallucination risk. Best when you need a numeric score rather than qualitative feedback.

## Known failure modes

- Missing 'text' query parameter returns an error
- Empty string input may return zero or undefined scores
- Extremely short text (1–2 words) may yield unreliable or edge-case scores
- Non-English text may produce inaccurate syllable counts since formulas are English-calibrated
- Very long text strings may hit URL length limits for GET requests

## How this service works

Compute readability metrics for a block of text: Flesch Reading Ease score, Flesch-Kincaid grade level, and word/sentence/syllable statistics. Deterministic formulas — useful for checking documentation, prompts and agent output clarity. Use this when an agent needs to flesch reading-ease and grade level for any text.

## Output

Returns a JSON object with the Flesch Reading Ease score (0–100 scale, higher = easier), Flesch-Kincaid grade level (US school grade equivalent), total word count, total sentence count, and total syllable count for the submitted text.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "text"
     ],
     "properties": {
      "text": {
       "type": "string",
       "description": "Text"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentstoolshub-readability-metrics-e6984505/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentstoolshub.com](https://www.zero.xyz/host/agentstoolshub.com/llms.txt)