docs: Clarify signal agents and decisioning platforms

.changeset/metal-hats-agree.md

@@ -0,0 +1,2 @@
+---
+---

docs/intro.mdx

@@ -75,7 +75,7 @@ Platforms that evaluate sellers and audiences, and execute buying strategies:
 MCP servers that provide:
 - **Signal Discovery**: Finding relevant signals (audiences, contextual, geographical, temporal) using natural language
 - **Signal Activation**: Pushing signals to decisioning platforms
-- **Integration**: Connects signal platforms to orchestration via MCP
+- **Integration**: Exposes data provider capabilities via MCP
 
 #### Sales Agent (Right, Bottom)
 MCP servers that provide:
@@ -142,8 +142,8 @@ The creative flow operates in parallel with the business and technical flows, en
 Each AdCP protocol operates within this ecosystem:
 
 ### 🎯 Signals Activation Protocol
-- **Scope**: Works with **signal platforms** to discover and activate signals directly on **decisioning platforms**
-- **Integration**: Direct integration between signal agents and decisioning platforms (DSPs, injective platforms)
+- **Scope**: Works with **signal agents** to discover and activate signals directly on **decisioning platforms**
+- **Integration**: Direct integration between signal agents and decisioning platforms (DSPs, SSPs, ad servers)
 - **Workflow**: Find signals → Direct activation on target platform → Ready for campaign use
 
 ### 📍 Curation Protocol (Coming Soon)
@@ -152,7 +152,7 @@ Each AdCP protocol operates within this ecosystem:
 - **Workflow**: Define requirements → Find inventory → Package with signals
 
 ### 💰 Media Buy Protocol
-- **Scope**: Works primarily with **decisioning platforms** (DSPs, injective platforms)
+- **Scope**: Works primarily with **decisioning platforms** (DSPs, SSPs, ad servers)
 - **Integration**: Executes campaigns using curated inventory and activated signals
 - **Workflow**: Set objectives → Execute buys → Optimize performance
 
@@ -240,7 +240,7 @@ Generate and optimize creative assets using AI-powered agents.
 
 AI is buying ads. Make sure it can buy yours.
 
-If you operate a signal platform, DSP, or ad tech solution, AdCP lets AI agents discover and purchase your inventory. [Review the Protocol Specifications](/docs/signals/specification) to get started.
+If you operate a data platform, DSP, or ad tech solution, AdCP lets AI agents discover and purchase your inventory. [Review the Protocol Specifications](/docs/signals/specification) to get started.
 
 ## For Advertisers & Agencies
 

docs/reference/glossary.mdx

@@ -67,11 +67,14 @@ Size unit representing unique device identifiers (cookies, mobile IDs) - typical
 **Device Type** (Media Buy Protocol)
 Targeting dimension for platform types: mobile, desktop, tablet, CTV, audio, DOOH.
 
+**Decisioning Platform**
+Technical infrastructure that selects which ad to serve at impression time. Receives activated signals and executes campaigns. Examples: DSPs (The Trade Desk), SSPs (Index Exchange, OpenX, PubMatic), ad servers (Google Ad Manager, Kevel).
+
 **DOOH (Digital Out-of-Home)**
 Digital advertising displayed on screens in public spaces such as billboards, transit stations, airports, and retail locations. Uses CPM or flat_rate pricing with parameters for SOV, duration, and venue targeting.
 
 **DSP (Demand-Side Platform)**
-Technology platform that allows advertisers to buy advertising inventory programmatically.
+A type of decisioning platform that allows advertisers to buy advertising inventory programmatically.
 
 ## E
 
@@ -163,21 +166,30 @@ Pricing model based on a percentage of media spend rather than fixed CPM.
 
 ## S
 
+**Sales Agent**
+An MCP server that exposes publisher inventory for discovery and purchase. Handles product discovery, media buy creation, and campaign management. Examples: Publisher ad servers exposing AdCP interfaces, sales house platforms.
+
 **Screen Time**
 Total duration an ad was displayed across all DOOH screens, measured in seconds. Used for DOOH delivery reporting.
 
 **Seat**
-A specific advertising account within a platform, typically representing a brand or campaign.
+A specific advertising account within a decisioning platform, typically representing a brand or campaign.
 
 **Segment ID**
 The specific identifier used for signal activation, may differ from signal_id.
 
 **Share of Voice (SOV)**
 Percentage of available ad inventory allocated to a specific advertiser in DOOH loops. Expressed as 0.0-1.0 (e.g., 0.15 = 15% SOV).
 
+**Signal Agent**
+An MCP server that provides signal discovery and activation services. Enables natural language audience discovery and deploys signals to decisioning platforms. Can be private (owned by a single principal) or marketplace (licensing data to multiple principals). Examples: LiveRamp, Experian, Peer39.
+
 **Size Unit** (Signals Protocol)
 The measurement type for signal size: individuals, devices, or households.
 
+**SSP (Supply-Side Platform)**
+A type of decisioning platform that helps publishers sell advertising inventory programmatically. SSPs connect to multiple demand sources and make ad selection decisions. Examples: Index Exchange, OpenX, PubMatic, Magnite.
+
 ## T
 
 **Takeover**

docs/signals/specification.mdx

@@ -35,10 +35,10 @@ The Signals Activation Protocol operates within the broader [AdCP Ecosystem Laye
 Every signal discovery request involves two key roles:
 
 #### Orchestrator
-The platform or system making the API request to the signal platform:
+The platform or system making the API request to the signal agent:
 - **Examples**: Scope3, Claude AI assistant, trading desk platform, campaign management tool
 - **Responsibilities**: Makes API calls, handles authentication, manages the technical interaction
-- **Account**: Has technical credentials and API access to the signal platform
+- **Account**: Has technical credentials and API access to the signal agent
 
 #### Principal  
 The entity on whose behalf the request is being made:
@@ -48,7 +48,7 @@ The entity on whose behalf the request is being made:
 
 #### How This Works in Practice
 
-1. **Request Flow**: Orchestrator → Signal Platform (on behalf of Principal) → Decisioning Platform
+1. **Request Flow**: Orchestrator → Signal Agent (on behalf of Principal) → Decisioning Platform
 2. **Authentication**: Orchestrator authenticates with technical credentials
 3. **Authorization**: Principal's identity determines available signals and pricing
 4. **Activation**: Signals are activated for Principal's account on the decisioning platform
@@ -95,7 +95,7 @@ The entity on whose behalf the request is being made:
 
 #### Private Signal Agents
 Agents owned by the principal with exclusive access:
-- **Examples**: Walmart's internal signal platform, retailer first-party data, weather APIs, location providers
+- **Examples**: Walmart's internal data systems, retailer first-party data, weather APIs, location providers
 - **Business Model**: No signal costs (workflow orchestration only)
 - **Access**: Only visible and accessible to the owning principal
 - **Discovery**: Not discoverable by other principals
@@ -146,9 +146,9 @@ The identifier assigned by the decisioning platform after activation:
 - **Timing**: Only available after successful activation
 - **Variability**: May differ by platform and account for the same signal
 
-### Agent vs Data Provider
+### Signal Agent vs Data Provider
 
-- **Agent**: The signal platform facilitating access (e.g., LiveRamp, Experian)
+- **Signal Agent**: The MCP server facilitating signal access (e.g., LiveRamp, Experian)
 - **Data Provider**: The original source of the signal data (e.g., Polk, Acxiom, Peer39, weather services, location providers)
 
 A signal agent may host segments from multiple data providers in their marketplace.
@@ -268,14 +268,14 @@ Some operations (like signal activation) are asynchronous and include:
 Each MCP session involves two levels of identification:
 
 #### Orchestrator Authentication
-The technical credentials used by the orchestrator to authenticate with the signal platform:
+The technical credentials used by the orchestrator to authenticate with the signal agent:
 - **API Keys**: Technical access credentials for the orchestrator platform
 - **Session Scope**: Determines what operations the orchestrator can perform
-- **Platform Permissions**: What signal platforms the orchestrator can access
+- **Agent Permissions**: What signal agents the orchestrator can access
 
-#### Principal Authorization  
+#### Principal Authorization
 The principal's identity determines business-level access and pricing:
-- **Account Relationship**: Whether the principal has a direct relationship with the signal platform
+- **Account Relationship**: Whether the principal has a direct relationship with the signal agent
 - **Pricing Tier**: Negotiated rates, marketplace rates, or enterprise discounts
 - **Signal Access**: Private signals, premium segments, or marketplace-only access
 - **Billing Account**: Where usage charges are applied