Portable authority
Describe authority by meaning, not vendor tool names
A BYOAg host should be able to understand what an agent may do without knowing the agent’s internal tool names. Capabilities provide that shared semantic layer.
The permission envelope
Authority is an intersection
Connecting an agent does not grant every action available in an experience. Effective authority is the overlap of three independent boundaries.
1 · Connection
May this installation connect?
Pairing establishes a durable, revocable relationship with a specific agent installation.
2 · Engagement
What may it do here?
The signed descriptor narrows authority for one experience and one operating context.
3 · Runtime
Is this action allowed now?
The client still applies local policy before exposing or invoking a concrete tool.
Portable vocabulary
Operations express intent
Capabilities describe what an operation means. Concrete APIs, MCP tools, and function names remain implementation details that can differ between platforms.
- read
- reveal
- create
- modify
- delete
- execute
- transact
- communicate
- delegate
- administer
Effects and data
Qualifiers make risk legible
A capability can also express the resource it affects, the classes of data involved, whether an effect is reversible, and where confirmation is required.
These qualifiers let clients reason about risk without pretending every platform exposes the same interface.
Resolution
From semantic contract to concrete tool
An experience can publish a capability contract. A compatible host may then map that meaning to its own callable surface.
Capability contract
{
"id": "game.move.submit",
"operation": "execute",
"resource": "current_match",
"effects": ["changes_shared_state"],
"confirmation": "policy_driven"
}Host-specific mapping
{
"tool": "arena_submit_move",
"satisfies": "game.move.submit",
"transport": "mcp"
}Portable skills
Skills declare what they need
A skill can declare required and optional capabilities. A future resolver can compare them with the signed engagement and the client’s local mappings before activation.
Required
All must resolve
If one is missing, the skill remains unavailable and explains the unmet requirement.
Optional
Graceful enhancement
Optional capabilities can unlock richer behavior without preventing the core skill from running.
Namespaces and versions
Stable meaning without one global catalog
- Use a stable namespace for domain-specific capabilities.
- Keep identifiers semantic; do not encode a vendor function name.
- Version breaking changes to meaning or required behavior.
- Prefer small, composable capabilities over broad claims of unrestricted access.