# index_equation [MAINTENANCE] 06df6ab3 — index ONE Word equation (OMML) 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. omml_or_latex is auto-detected: a string starting with '<' is treated as raw OMML XML (stored as-is); anything else is treated as LaTeX source (real OMML is generated best-effort — pure-Python latex2mathml piped through a hand-written MathML->OOXML mapper; returns null omml on an unsupported construct, never an error). Before inserting, the normalized LaTeX is fuzzy-matched against every equation already stored for this document — a near-duplicate is NOT silently dropped (the equation is still inserted) but IS surfaced via near_duplicates:[{equation_id, matched_id, matched_latex, score}] so you can spot accidental re-derivations. Returns {equation, near_duplicates}. 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_equation`. HTML page: https://policylayer.com/tools/io-github-ajc3xc-meridian/index-equation ## Facts - Tool: `index_equation` - 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: 5 (2 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). | | `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. | | `omml_or_latex` | string | yes | Raw OMML XML (starts with '<') OR a LaTeX source string. | | `semantic_label` | string | no | Optional human label for the equation (e.g. 'mass-energy equivalence'). | 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_equation", "arguments": { "doc": "", "omml_or_latex": "" } } } ``` ## Why index_equation is rated Medium This tool writes/indexes an equation into an existing document structure store. It creates or modifies stored data (adding an equation index entry) but does not irreversibly delete data, execute code, or involve financial operations. The operation is a structured write to a persistent store, making Write the appropriate category. From the tool's own definition: "index ONE Word equation (OMML) against a document already stored in the doc-structure store — populated by ingest_document" Risk signals: Bulk/mass operation — affects multiple targets ## Use case AI agents use index_equation 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_equation": { "limits": [ { "counter": "index_equation_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