io.github.agenson-horrowitz/agent-output-guard
NPM · @AGENSON-HORROWITZ/AGENT-OUTPUT-GUARD-MCP · SCANNED SEP 24
Validate and verify data from other agents before acting on it. Zero LLM costs.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security98
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- No install/post-install scripts declared.Pass
- 32 of 97 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency45
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 174 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability79
- AI-judged instruction clarity (excellent).Pass
- Tool/resource definitions use about 521 tokens (~104/item across 5 items; 5 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management83
- Stability observed for 25 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the io.github.agenson-horrowitz/agent-output-guard MCP server?
io.github.agenson-horrowitz/agent-output-guard runs locally as an npm package, launched with npx -y @agenson-horrowitz/agent-output-guard-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · @agenson-horrowitz/agent-output-guard-mcp
claude mcp add agenson-horrowitz-agent-output-guard -- npx -y @agenson-horrowitz/agent-output-guard-mcp
{
"mcpServers": {
"agenson-horrowitz-agent-output-guard": {
"command": "npx",
"args": [
"-y",
"@agenson-horrowitz/agent-output-guard-mcp"
]
}
}
} {
"servers": {
"agenson-horrowitz-agent-output-guard": {
"command": "npx",
"args": [
"-y",
"@agenson-horrowitz/agent-output-guard-mcp"
]
}
}
} codex mcp add agenson-horrowitz-agent-output-guard -- npx -y @agenson-horrowitz/agent-output-guard-mcp
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"agenson-horrowitz-agent-output-guard": {
"type": "local",
"command": [
"npx",
"-y",
"@agenson-horrowitz/agent-output-guard-mcp"
],
"enabled": true
}
}
} openclaw mcp add agenson-horrowitz-agent-output-guard --command npx --arg -y --arg @agenson-horrowitz/agent-output-guard-mcp
mcp_servers:
agenson-horrowitz-agent-output-guard:
command: "npx"
args: ["-y", "@agenson-horrowitz/agent-output-guard-mcp"] {
"McpServers": {
"agenson-horrowitz-agent-output-guard": {
"Transport": "stdio",
"Command": "npx",
"Arguments": [
"-y",
"@agenson-horrowitz/agent-output-guard-mcp"
]
}
}
} assistant mcp add agenson-horrowitz-agent-output-guard -t stdio -c npx -a -y @agenson-horrowitz/agent-output-guard-mcp
{
"mcpServers": {
"agenson-horrowitz-agent-output-guard": {
"command": "npx",
"args": [
"-y",
"@agenson-horrowitz/agent-output-guard-mcp"
]
}
}
} Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 23 Sept 26 −3
- Stability: pass → 0.80 functional
- 22 Sept 26 +1
- Stability: 0.97 → pass security
- 21 Sept 26 0
- Security disclosure: unverified → fail ▼ functional
- 20 Sept 26 +1
- Security disclosure: fail → unverified ▼ functional
- 18 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.
- 17 Sept 26 −3
- Stability: pass → 0.83 functional
- 16 Sept 26 +1
- Stability: 0.97 → pass security
- 14 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 24 Sept 2026 · Analysed npm/@agenson-horrowitz/agent-output-guard-mcp@1.0.8
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | npm |
Background: How many MCP packages publish verified provenance →
Dependencies 97 packages
| Packages resolved | 97 |
|---|---|
| Stale | 32 |
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
cross_reference_check ~87
Compare data from multiple agents for consistency and detect discrepancies. Essential for multi-agent coordination. Returns consistency score and detailed comparison.
| Name | Type | Req | Description |
|---|---|---|---|
| comparison_fields | array | – | Specific fields to compare across datasets |
| primary_data | – | yes | Primary data object to verify |
| reference_data | array | yes | Array of reference data from other agents |
| tolerance_level | string | – | How strict to be with differences |
No output schema declared.
No examples provided.
detect_hallucination_markers ~104
Scan agent output for common hallucination patterns, uncertainty markers, and fabrication indicators. Critical for multi-agent reliability. Returns detailed analysis and confidence score.
| Name | Type | Req | Description |
|---|---|---|---|
| content_type | string | – | Type of content being analyzed for context-aware detection |
| sensitivity_level | string | – | Detection sensitivity (high = more conservative) |
| source_agent | string | – | Identifier of the agent that generated this text |
| text | string | yes | Text output from another agent to analyze |
No output schema declared.
No examples provided.
output_consistency_score ~111
Calculate overall consistency score for agent output including internal logic, format consistency, and reliability indicators. Returns comprehensive reliability assessment.
| Name | Type | Req | Description |
|---|---|---|---|
| context | string | – | Context or prompt that generated this output |
| expected_format | object | – | Expected structure/format of the output |
| historical_outputs | array | – | Previous outputs from same agent for pattern analysis |
| output | – | yes | Complete output from an agent (text, data, or structured response) |
| source_agent | string | – | Agent identifier for tracking reliability over time |
No output schema declared.
No examples provided.
validate_data_freshness ~119
Check if data from another agent is recent and valid based on timestamps, staleness indicators, and expected update frequencies. Prevents acting on outdated information.
| Name | Type | Req | Description |
|---|---|---|---|
| data | – | yes | Data object to check for freshness |
| expected_update_frequency | string | – | How often this data should be updated |
| max_age_hours | number | – | Maximum acceptable age in hours |
| source_agent | string | – | Agent that provided this data |
| timestamp_field | string | – | Field name containing timestamp (e.g., "created_at", "updated_at") |
No output schema declared.
No examples provided.
verify_json_schema ~100
Validate JSON data from another agent against expected schema. Essential for preventing malformed data propagation in multi-agent workflows. Returns validation status, errors, and confidence score.
| Name | Type | Req | Description |
|---|---|---|---|
| data | – | yes | JSON data received from another agent |
| schema | object | yes | Expected JSON schema for validation |
| source_agent | string | – | Identifier of the agent that provided this data (for audit trail) |
| strict_validation | boolean | – | Enable strict validation mode (fails on additional properties) |
No output schema declared.
No examples provided.
What is the io.github.agenson-horrowitz/agent-output-guard MCP server?
io.github.agenson-horrowitz/agent-output-guard is an MCP server listed in the public MCP registry as io.github.agenson-horrowitz/agent-output-guard. Validate and verify data from other agents before acting on it. Zero LLM costs. This page covers its npm package (@agenson-horrowitz/agent-output-guard-mcp).
Is the io.github.agenson-horrowitz/agent-output-guard MCP server safe to use?
io.github.agenson-horrowitz/agent-output-guard scores 82 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 24 September 2026. It declares no install or post-install scripts. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the io.github.agenson-horrowitz/agent-output-guard MCP server expose?
io.github.agenson-horrowitz/agent-output-guard exposes 5 tools: verify_json_schema, detect_hallucination_markers, validate_data_freshness, cross_reference_check, output_consistency_score. Their descriptions and schemas cost roughly 521 tokens of context every time the server is loaded.
Is the io.github.agenson-horrowitz/agent-output-guard MCP server still maintained?
io.github.agenson-horrowitz/agent-output-guard is still listed as active in the MCP registry. We last reached this channel on 24 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What licence is the io.github.agenson-horrowitz/agent-output-guard MCP server under?
io.github.agenson-horrowitz/agent-output-guard declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.