docs(skill): replace dist/schemas/ paths with SDK-agnostic probe list in call-adcp-agent

.changeset/fix-call-adcp-agent-schema-paths.md

@@ -0,0 +1,4 @@
+---
+---
+
+Fix `skills/call-adcp-agent/SKILL.md` bundled-schema path references: replace hardcoded `dist/schemas/` paths (spec-repo source layout, wrong for all SDK consumers) with an ordered probe list (local SDK install → local spec-repo build → HTTP canonical URL at `https://adcontextprotocol.org/schemas/v3/bundled/`). Add underscore→hyphen translation note for tool names in filenames. Removes false claim that `npm run sync-schemas` exists across all SDKs.

skills/call-adcp-agent/SKILL.md

@@ -9,7 +9,7 @@ type: cross-cutting
 
 ## Overview
 
-AdCP (Ad Context Protocol) agents expose a fixed tool surface (`get_products`, `create_media_buy`, `get_signals`, …) over MCP or A2A. Tool names come from `get_adcp_capabilities`; exact request/response shapes live in the spec's bundled JSON Schemas at `dist/schemas/<adcp-version>/bundled/<protocol>/<tool>-{request,response}.json` (or via `get_schema` when the agent exposes it). This skill teaches the invariants that don't live cleanly in any schema: cross-tool patterns, async flow, error recovery.
+AdCP (Ad Context Protocol) agents expose a fixed tool surface (`get_products`, `create_media_buy`, `get_signals`, …) over MCP or A2A. Tool names come from `get_adcp_capabilities`; exact request/response shapes are available via `get_schema` when the agent exposes it, or from the spec's bundled JSON Schemas at `https://adcontextprotocol.org/schemas/v3/bundled/<protocol>/<tool>-{request,response}.json`. This skill teaches the invariants that don't live cleanly in any schema: cross-tool patterns, async flow, error recovery.
 
 ## When to Use
 
@@ -25,7 +25,12 @@ Walk these in order on first contact:
 1. **Agent card** (A2A) or **`tools/list`** (MCP): returns tool NAMES. AdCP MCP servers no longer publish per-tool parameter schemas in `tools/list` — everything shows `{type: 'object', properties: {}}`. Don't try to infer shape from here.
 2. **`get_adcp_capabilities`**: returns supported protocols (`media_buy`, `signals`, `creative`, …), AdCP major versions, feature flags. Tells you WHICH tools this agent supports, not how to call them.
 3. **`get_schema(tool_name)`** *(when the agent exposes it — pending standardization in [#3057](https://github.com/adcontextprotocol/adcp/issues/3057), not yet universal)*: returns the JSON Schema for a tool's request/response. Preferred over reading bundled schemas when available.
-4. **Bundled schemas** (offline, authoritative): `dist/schemas/<adcp-version>/bundled/<protocol>/<tool>-request.json` and `-response.json`. The adcp main repo publishes these; SDKs sync them (`npm run sync-schemas` in `@adcp/client`, equivalents in other SDKs). Substitute your target AdCP major version in the path.
+4. **Bundled schemas** (authoritative, no agent required): probe in order until one resolves —
+   1. Local SDK cache — path varies by SDK (e.g., `@adcp/client` caches at `schemas/cache/<semver>/bundled/<protocol>/<tool>-request.json`; check your SDK's README if this path doesn't exist)
+   2. Local spec-repo build: `dist/schemas/<semver>/bundled/<protocol>/<tool>-request.json`
+   3. HTTP (always available): `https://adcontextprotocol.org/schemas/v3/bundled/<protocol>/<tool>-request.json` — use the major alias matching `adcp_version` (`"3.x"` → `v3`)
+
+   Tool names use hyphens in filenames, not underscores: `create-media-buy-request.json` for `create_media_buy`. For local probes, `<semver>` is a full version string (e.g., `3.0.0`).
 
 ## Non-obvious rules every buyer must follow
 
@@ -244,12 +249,12 @@ Priority order:
 
 1. Re-read the failure's `issues[]`. The pointer list plus this skill covers 80% of cases.
 2. Call `get_schema(tool_name)` if the agent exposes it (see [#3057](https://github.com/adcontextprotocol/adcp/issues/3057) for the pending standard).
-3. Read the bundled JSON Schema at `dist/schemas/<adcp-version>/bundled/<protocol>/<tool>-request.json`.
+3. Fetch the bundled JSON Schema — probe in order (see Discovery chain step 4 for full probe sequence): local SDK cache, `dist/schemas/<semver>/bundled/<protocol>/<tool>-request.json` (spec-repo build), or `https://adcontextprotocol.org/schemas/v3/bundled/<protocol>/<tool>-request.json` (HTTP, always available). Tool names use hyphens in filenames (`create-media-buy-request.json` for `create_media_buy`).
 4. Consult the per-protocol skill in this repo (`skills/adcp-media-buy/`, `skills/adcp-creative/`, …) for specialism-specific patterns.
 
 ## Related
 
 - [Calling an agent (docs)](https://adcontextprotocol.org/docs/protocol/calling-an-agent) — human-readable narrative form of this skill
 - `skills/adcp-media-buy/`, `skills/adcp-creative/`, `skills/adcp-signals/`, `skills/adcp-governance/`, `skills/adcp-si/`, `skills/adcp-brand/` — per-protocol task skills (layered on top of this one)
 - `@adcp/client/skills/build-seller-agent/SKILL.md` — building agents on the other side of the call
-- `dist/schemas/<adcp-version>/bundled/` — canonical JSON Schemas (every tool, pinned to the AdCP version)
+- [Bundled JSON Schemas](https://adcontextprotocol.org/schemas/v3/bundled/) — fully dereferenced schemas for every tool, pinned to the AdCP version