mcp-vdd

Clarify Spec

vdd_clarify

Read-onlyIdempotent

Scan a spec file to list every [NEEDS CLARIFICATION] marker, [e.g.] placeholder, and happy-path acceptance criterion missing an edge-case match. Read-only; host applies the resolutions.

Instructions

VDD Phase 4b: Clarify an existing spec — scans vdd/specs//spec.md and returns the items to resolve: every [NEEDS CLARIFICATION] marker, [e.g.] placeholder, and happy-path acceptance criterion (AC) still needing an edge-case counterpart (AC-E*). Read-only; returns the list without editing the file (the host agent then applies the resolutions). Pass feature (spec directory name). Run after vdd_specify when a spec has unresolved markers; to author a brand-new spec use vdd_specify instead. Parameter relationships: feature must be the exact spec directory name created by vdd_specify.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`feature`	Yes	Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
`projectRoot`	No	Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")	.

Output Schema

TableJSON Schema

Name	Required	Description
`_sdt`	Yes	Strategy-and-Tactic instructions for the next step
`error`	No	Error message when the phase fails
`_phase`	Yes	VDD phase that produced this result
`output`	No	Additional structured phase output
`success`	Yes	Whether the phase completed successfully
`artifact`	No	Primary artifact produced or returned
`gateResult`	No	Quality-gate result, when the phase runs a gate

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.9.0Oct 2, 2026

changedInput schema / properties / feature / description

Previous value: -"Feature name (spec directory name)"New value: +"Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., \"user-auth\"); must reference a directory created earlier by vdd_specify"

changedInput schema / properties / projectRoot / description

Previous value: -"Project root: directory that constitution.md and the vdd/ folder are written to and resolved against (default \".\")"New value: +"Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default \".\")"

Changed1 schema field changedv0.1.3Sep 24, 2026

changedInput schema / properties / projectRoot / description

Previous value: -"Path to project root directory"New value: +"Project root: directory that constitution.md and the vdd/ folder are written to and resolved against (default \".\")"

Changed1 schema field changedv0.1.2Sep 24, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": false,
+  "properties": {
+    "_phase": {
+      "description": "VDD phase that produced this result",
+      "type": "string"
+    },
+    "_sdt": {
+      "description": "Strategy-and-Tactic instructions for the next step",
+      "type": "string"
+    },
+    "artifact": {
+      "description": "Primary artifact produced or returned",
+      "type": "string"
+    },
+    "error": {
+      "description": "Error message when the phase fails",
+      "type": "string"
+    },
+    "gateResult": {
+      "additionalProperties": false,
+      "description": "Quality-gate result, when the phase runs a gate",
+      "properties": {
+        "checks": {
+          "description": "Number of checks run",
+          "type": "number"
+        },
+        "passed": {
+          "description": "Whether the quality gate passed",
+          "type": "boolean"
+        },
+        "total": {
+          "description": "Total number of checks",
+          "type": "number"
+        }
+      },
+      "required": [
+        "passed",
+        "checks",
+        "total"
+      ],
+      "type": "object"
+    },
+    "output": {
+      "additionalProperties": {},
+      "description": "Additional structured phase output",
+      "propertyNames": {
+        "type": "string"
+      },
+      "type": "object"
+    },
+    "success": {
+      "description": "Whether the phase completed successfully",
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success",
+    "_phase",
+    "_sdt"
+  ],
+  "type": "object"
+}

First observedv0.1.0Sep 24, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is covered. The description adds non-obvious behavior anyway: it scans a specific path, returns the list without editing, and the host agent applies resolutions — helpful context beyond structured data, though it omits the return shape details (covered by the output schema).

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

Conciseness4/5

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

Front-loaded with phase and action, then scope and routing. A bit dense with bracketed marker syntax and a trailing 'Parameter relationships' sentence that partly duplicates the schema, but nothing is genuinely wasted.

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

Completeness5/5

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

With rich annotations, a full schema, and an output schema describing the returned items, the description covers purpose, sequencing, non-mutation behavior, and sibling routing. Nothing an agent needs to invoke it correctly is missing.

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

Parameters3/5

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

Schema coverage is 100%, and the schema description for 'feature' already states it must reference a directory created by vdd_specify and be kebab-case. The description's restatement of that relationship adds little beyond the schema, so baseline 3 is appropriate.

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

Purpose5/5

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

Specific verb+resource ('Clarify an existing spec'), names its phase, and states exactly what it returns: [NEEDS CLARIFICATION] markers, [e.g.] placeholders, and ACs lacking AC-E counterparts. It explicitly differentiates from the sibling vdd_specify by scope (existing vs brand-new spec).

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

Usage Guidelines5/5

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

Gives explicit sequencing ('Run after vdd_specify'), a triggering condition ('when a spec has unresolved markers'), and an exclusion with the alternative tool ('to author a brand-new spec use vdd_specify instead'). The agent is fully routed.

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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