phi-mcp-server

How PRISM reaches its suggestions

get_methodology

Read-onlyIdempotent

Explains how PRISM scores results across five health areas and their weights, then links to the full methodology and cited clinical guidelines.

Instructions

Explains how PRISM scores results (five health areas and their weights) and links to the full methodology, including the clinical guidelines it cites.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "get_methodology"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description
`note`	Yes	Decision-support disclaimer and synthetic-data rule.
`source`	Yes	Attribution.
`next_step`	Yes	The one next step: read this last and act on it.
`phi_score`	Yes	Plain-English summary of how the 0-100 Phi Longevity Score is computed.
`agent_docs_url`	Yes	Agent integration docs.
`methodology_url`	Yes	Full public methodology page.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.7.0Nov 6, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": false,
+  "properties": {
+    "agent_docs_url": {
+      "description": "Agent integration docs.",
+      "type": "string"
+    },
+    "methodology_url": {
+      "description": "Full public methodology page.",
+      "type": "string"
+    },
+    "next_step": {
+      "additionalProperties": false,
+      "description": "The one next step: read this last and act on it.",
+      "properties": {
+        "call_tool": {
+          "description": "The tool to call next, when the next step is a call.",
+          "type": "string"
+        },
+        "for_you": {
+          "description": "The one thing to do next, as an instruction to you (the assistant).",
+          "type": "string"
+        },
+        "url": {
+          "description": "The link to give the person, when the next step is theirs to open.",
+          "type": "string"
+        }
+      },
+      "required": [
+        "for_you"
+      ],
+      "type": "object"
+    },
+    "note": {
+      "description": "Decision-support disclaimer and synthetic-data rule.",
+      "type": "string"
+    },
+    "phi_score": {
+      "description": "Plain-English summary of how the 0-100 Phi Longevity Score is computed.",
+      "type": "string"
+    },
+    "source": {
+      "description": "Attribution.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "phi_score",
+    "methodology_url",
+    "agent_docs_url",
+    "note",
+    "source",
+    "next_step"
+  ],
+  "type": "object"
+}

First observedv0.6.3Jul 31, 2026

TDQS

A3.5/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare this as a safe, read-only, idempotent, non-destructive operation. The description adds useful content scope by noting the five health areas, weights, methodology link, and cited clinical guidelines, but does not disclose further behavioral traits such as freshness or whether the explained methodology is static.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single well-structured sentence that front-loads the main purpose and includes only relevant details. Every phrase, including the parenthetical about health areas and weights, adds useful specificity without waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter read-only explainer with an output schema and safety annotations, the description is largely complete. It could be slightly improved by clarifying that this returns general methodology rather than personalized results, but the core scope is adequately covered.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so parameter semantics are not a concern. The empty schema is self-evident, and the description correctly does not introduce parameter details that would be irrelevant.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: it explains how PRISM scores results, including five health areas, weights, a link to full methodology, and clinical guidelines. This is clear and distinct in substance from siblings like full_prism_report, though it does not explicitly name alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains what the tool contains but gives no explicit guidance on when to call it versus alternatives such as full_prism_report, sample_prism_report, or quick_check. Usage is only weakly implied by the word 'Explains'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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