# index_figure

[MAINTENANCE] c623e648 — index ONE figure into the SEMANTIC figure index against a document already stored in the doc-structure store — populated by ingest_document (which registers a docx/latex document's structure here in addition to storing the flat note text). Pass the SAME source/path you ingested under as doc. This is the figure parallel of index_equation and is COMPLEMENTARY to the structural kind='figure' section-tree placement (it adds caption dedup + similarity, it does not replace placement). Provide file_path and/or caption. Before inserting, the normalized caption is fuzzy-matched against every figure already indexed for this document — a near-duplicate is NOT silently dropped (the figure is still inserted) but IS surfaced via near_duplicates:[{figure_id, matched_id, matched_caption, score}] so you can spot an accidental re-index. The referenced file_path is checked on disk: a missing file is FLAGGED (file_exists on the row + a missing_files entry), never a hard failure. Returns {figure, near_duplicates, missing_files}. Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata are sent to and stored in Meridian's service; self-hosted deployments keep them in the configured local SQLite/Postgres database. This data is visible in the dashboard/API and later project context or handoffs. Delete individual tasks, notes, or decisions where supported, or delete the project/account using the documented controls. Do not include secrets.

Agent View of the PolicyLayer registry record for `index_figure`. HTML page: https://policylayer.com/tools/io-github-ajc3xc-meridian/index-figure

## Facts

- Tool: `index_figure`
- Server: Meridian (`@meridianmcp/mcp`) — https://policylayer.com/tools/io-github-ajc3xc-meridian.md
- Install: `npx -y @meridianmcp/mcp`
- Homepage: https://github.com/meridianmcp/Meridian
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server CORS policy: *
- Server rate-limited: no
- Parameters: 6 (1 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `doc` | string | yes | The stored document's source (the path/URL you ingested it under via ingest_document, which registers a docx/latex document in the doc-structure store). |
| `caption` | string | no | The figure's caption (drives normalized-caption dedup/similarity). |
| `file_path` | string | no | Path to the figure's asset on disk (checked for existence; missing is flagged, not fatal). |
| `project_id` | string | no |  |
| `project_name` | string | no | Project name — an alternative to project_id; resolved to the id internally. project_id wins if both are given. |
| `semantic_label` | string | no | Optional human label for the figure (e.g. 'apparatus diagram'). |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "index_figure",
    "arguments": {
      "doc": "<doc>"
    }
  }
}
```

## Why index_figure is rated Medium

This tool writes a figure entry into a semantic index store. It creates/modifies index data (caption deduplication, similarity entries) but does not execute code, delete data, or involve financial operations. It is reversible in principle (index entries can be removed), making Write the appropriate category. Severity is low since it only affects an internal search/semantic index with limited blast radius.

From the tool's own definition: "index ONE figure into the SEMANTIC figure index...adds caption dedup + similarity, it does not replace placement"

Risk signals: Accepts file system path (file_path) · Bulk/mass operation — affects multiple targets

## Use case

AI agents use index_figure to create or update resources in Meridian, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Meridian environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Meridian:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "index_figure": {
      "limits": [
        {
          "counter": "index_figure_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Meridian (174)

- `archive_decision` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/archive-decision.md
- `batch_mutate` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/batch-mutate.md
- `claim_sprint_item` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/claim-sprint-item.md
- `clear_capability_profile` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clear-capability-profile.md
- `clone_profile_layer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clone-profile-layer.md
- `delete_custom_hook` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-custom-hook.md
- `delete_note` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-note.md
- `delete_sprint_item_pointer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-sprint-item-pointer.md
- `fan_out_sprint_items` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/fan-out-sprint-items.md
- `purge_ai_log` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/purge-ai-log.md
- `record_handoff_correction` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/record-handoff-correction.md
- `release_docx_region_claims` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/release-docx-region-claims.md
- `request_hitl` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/request-hitl.md
- `reset_plugin_override` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/reset-plugin-override.md
- `reset_profile_layer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/reset-profile-layer.md
- `complete_wave_gate` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/complete-wave-gate.md
- `execute_batch` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/execute-batch.md
- `prospect_symbol` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/prospect-symbol.md
- `run_verification` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/run-verification.md
- `start_session` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/start-session.md
- `analyze_model_efficiency` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/analyze-model-efficiency.md
- `analyze_sprint` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/analyze-sprint.md
- `batch_read` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/batch-read.md
- `find_outputs_by_source` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-outputs-by-source.md
- `find_similar_equation` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-equation.md
- `find_similar_figure` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-figure.md
- `find_similar_table` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-table.md
- `find_symbol_usages` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-symbol-usages.md
- `get_agent_instructions` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/get-agent-instructions.md
- `get_blog_posts` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/get-blog-posts.md
- …and 144 more: https://policylayer.com/tools/io-github-ajc3xc-meridian.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-ajc3xc-meridian · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-ajc3xc-meridian
