# Proposition 65 (remote · prop65.toolstop.dev)

Is a chemical on California's Proposition 65 list, and does it need a warning?

- Trust score: 57/100 (low)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-14

## Components

- remote · `prop65.toolstop.dev`: 57/100 (this document), [markdown](https://verifymcp.io/servers/dev-toolstop-prop65/prop65.md), [page](https://verifymcp.io/servers/dev-toolstop-prop65/prop65)
- npm · `@toolstop/prop65`: 76/100, [markdown](https://verifymcp.io/servers/dev-toolstop-prop65/toolstop-prop65.md), [page](https://verifymcp.io/servers/dev-toolstop-prop65/toolstop-prop65)

## Channel facts

- Endpoint: `https://prop65.toolstop.dev`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-14.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 4 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS check failed: the endpoint is reachable over plaintext HTTP.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 69/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 905 tokens (~226/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 10/100
  - Stability observed for 3 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add --transport http dev-toolstop-prop65 https://prop65.toolstop.dev/
```

### Codex

```toml
[mcp_servers.dev-toolstop-prop65]
url = "https://prop65.toolstop.dev/"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "dev-toolstop-prop65": {
      "type": "remote",
      "url": "https://prop65.toolstop.dev/",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add dev-toolstop-prop65 --url https://prop65.toolstop.dev/ --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  dev-toolstop-prop65:
    url: "https://prop65.toolstop.dev/"
```

### Other

```json
{
  "mcpServers": {
    "dev-toolstop-prop65": {
      "type": "http",
      "url": "https://prop65.toolstop.dev/"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-14 (score 57, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-08-12 (score 56, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-08-11 (score 55)

First indexed and scored.

## MCP tools (4)

### `check_prop65` (~146 tokens)

Is this chemical on the Proposition 65 list

Look up a chemical by CAS number or name and report whether it is on California's Proposition 65 list. Use this when deciding whether a product sold into California needs a warning label. Returns every matching entry with the toxicity endpoint, the listing mechanism, the date listed and the safe-harbour level where one has been adopted, plus whether the entry has since been delisted. A `not_found` result does not mean the chemical is safe or unregulated: it means this edition of this one list has no entry under that name or number.

Input parameters:

- `query` (string, required): A CAS number such as 71-43-2, or a chemical name such as Benzene.

Output parameters:

- `candidates` (array): Possible chemicals, when the name matched several entries.
- `delistedOnly` (boolean): True when every matching entry was listed and later removed.
- `edition` (string): The edition of the list this answer came from.
- `entries` (array): Each matching entry, including delisted ones, with its endpoint and safe-harbour level.
- `listed` (boolean): Whether an active (not delisted) entry exists. Present when status is `ok`.
- `notCovered` (array): What this answer does not establish. Present on both hits and misses.
- `status` (string): Outcome of the lookup. `not_found` is not a clearance. `ambiguous` means the name matched several entries and you should pick one or use a CAS number.

### `search_prop65` (~155 tokens)

Find listed chemicals by partial name

Search the Proposition 65 list for chemicals whose name contains a fragment. Use this when you do not have an exact name or a CAS number, or to survey a family of related substances. Returns matching chemicals with their CAS numbers, toxicity endpoints, listing dates and delisted flags, capped at a limit with `truncated` set when there were more. It searches names only, so it will not find a chemical listed under a synonym you did not search for, and a result here is not a determination that a warning is required.

Input parameters:

- `limit` (number): Maximum results to return. Defaults to 25.
- `term` (string, required): A fragment of a chemical name, such as 'benz' or 'chromium'.

Output parameters:

- `count` (number): How many entries matched in total.
- `edition` (string): The edition of the list this answer came from.
- `results` (array): The matching chemicals.
- `status` (string): Outcome of the lookup. `not_found` is not a clearance. `ambiguous` means the name matched several entries and you should pick one or use a CAS number.
- `truncated` (boolean): Whether more matched than were returned.

### `list_recent_listings` (~125 tokens)

Chemicals added to the list since a year

List the chemicals added to Proposition 65 on or after a given year. Use this to find recent additions, which matters because a warning is generally required twelve months after a chemical is listed, so a new entry starts a compliance clock. Returns active listings only, newest first, with their dates, and reports how many entries carry no parseable date and are therefore missing from the answer. It does not tell you whether any particular product is affected.

Input parameters:

- `since` (number, required): Four-digit year, from 1986 onwards. Prop 65 listings begin in 1987.

Output parameters:

- `count` (number): How many active chemicals were listed on or after that year.
- `edition` (string): The edition of the list this answer came from.
- `results` (array): The chemicals, newest first.
- `status` (string): Outcome of the lookup. `not_found` is not a clearance. `ambiguous` means the name matched several entries and you should pick one or use a CAS number.
- `undatedEntries` (number): Active entries with no parseable listing date, absent from this answer.

### `describe_prop65_list` (~111 tokens)

What this list is and what it covers

Report the size and edition of the embedded Proposition 65 list, and what the listing-mechanism codes mean. Use this to check how current the data is before relying on a lookup, or to interpret the `AB`, `SQE`, `FR` and `LC` codes on an entry. Returns counts of total, active and delisted entries, how many carry a CAS number, and the edition date. It reports on the data only and cannot tell you whether any product requires a warning.

Output parameters:

- `active` (number): Entries currently listed.
- `delisted` (number): Entries listed and later removed.
- `edition` (string): Edition date of the OEHHA list.
- `mechanisms` (object): Listing-mechanism codes and their meanings.
- `status` (string): Always ok.
- `total` (number): Entries in the embedded list, including delisted ones.
- `withCas` (number): Entries carrying at least one CAS number.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/dev-toolstop-prop65/prop65#diagnostics

## Score history

- 2026-08-14: 57
- 2026-08-13: 56
- 2026-08-12: 56
- 2026-08-11: 55

## Links

- Remote endpoint: https://prop65.toolstop.dev/
- Repository: https://github.com/toolstop/toolstop
- Website: https://prop65.toolstop.dev/
- Changelog RSS feed: https://verifymcp.io/servers/dev-toolstop-prop65/prop65.xml
- Changelog JSON feed: https://verifymcp.io/servers/dev-toolstop-prop65/prop65.json
- HTML version of this page: https://verifymcp.io/servers/dev-toolstop-prop65/prop65