Agent

An agent carries an explicit responsibility and chooses among its declared capabilities. A skill instead describes a reusable composition of steps.

Shape

source.tb

agent AgentName
    takes request as RequestType
    gives ResultType
    responsibility "Fulfill the declared AgentName responsibility using only authorized capabilities."
    uses SomeSkill
    callable_by strategy StrategyName

responsibility is mandatory, unique and nonempty. It describes the agent's role; it does not grant execution rights. uses lists available capabilities. callable_by declares authorized callers, which can be strategies or agents.

Typed invocation

agent_type.tb

module examples.agent_type

type ReviewRequest
    summary is Text

type ReviewResult
    verdict is Text

tool InspectRequest
    description "Inspect one request and return a review result."
    takes request as ReviewRequest
    gives ReviewResult

agent Reviewer
    takes request as ReviewRequest
    gives ReviewResult
    responsibility "Review the explicit request and return one typed final result."
    uses InspectRequest
    callable_by strategy RunReview

strategy RunReview
    takes request as ReviewRequest
    gives ReviewResult
    uses Reviewer
    do
        Reviewer
            with request as request
            into review
        give review

takes and gives declare an optional direct interface, never inferred from uses. Bind every declared input with with; into receives only the final result validated against gives. Intermediate capability observations are not implicitly the final result.

Agents without an explicit interface accept the simple invocation form, without with or into. For imported agents with explicit interfaces, the compiler resolves signatures from the project's source modules. Types retain their module identity and callers still require authorization. See Multi-module imports.

Single capability

agent_simple.tb

module examples.agent_simple

type DatasetRequest
    query is Text

type DatasetBrief
    summary is Text

tool SearchDatasets
    takes request as DatasetRequest
    gives DatasetBrief
    requires network

skill BuildDatasetBrief
    takes request as DatasetRequest
    gives DatasetBrief
    uses SearchDatasets
    do
        SearchDatasets
            with request as request
            into result
        give result

agent Researcher
    responsibility "Fulfill the declared Researcher responsibility using only authorized capabilities."
    uses BuildDatasetBrief
    callable_by strategy RunDatasetResearch

strategy RunDatasetResearch
    uses Researcher
    do
        Researcher

With one declared capability, Touba can select BuildDatasetBrief without a decision provider. Tool bindings and any required runtime inputs must still be supplied explicitly.

Multiple capabilities

agent_advanced.tb

module examples.agent_advanced

type DatasetRequest
    query is Text

type DatasetBrief
    summary is Text

tool SearchDatasets
    takes request as DatasetRequest
    gives DatasetBrief
    requires network

skill BuildDatasetBrief
    takes request as DatasetRequest
    gives DatasetBrief
    uses SearchDatasets
    do
        SearchDatasets
            with request as request
            into result
        give result

skill ReviewBrief
    takes brief as DatasetBrief
    gives DatasetBrief
    do
        human.approve
            with context as brief
            into approved

        give brief

agent Researcher
    responsibility "Fulfill the declared Researcher responsibility using only authorized capabilities."
    uses BuildDatasetBrief
    uses ReviewBrief
    callable_by strategy RunDatasetResearch

strategy RunDatasetResearch
    uses Researcher
    do
        Researcher

A configured provider proposes a capability and its named arguments. The runtime checks the target, types, caller authority and applicable resource scopes before executing it. See Governed agentic decision.

Authorized capabilities remain reusable across iterations, subject to the same budgets and checks. A capability being present in history does not make it unavailable.

Execution boundary

• An agent may select a function, tool, skill, agent or strategy declared in uses.
• Delegation does not silently union caller and callee resource authority.
• Memory and secret access require explicit scopes and tool contracts.
• Structured and native SDK interfaces return proposals; neither executes a provider call as a Touba action without runtime mediation.
• A strategy can distribute typed inputs across an agent with parallel. Invocations have isolated data and share run budgets.
• An agent can select an authorized strategy containing a parallel group; its own decision loop remains sequential.
• Coordination uses typed arguments and results, not free-form handoffs or automatic capability discovery.
• An authorized capability may be reused while its budgets allow it.

See Bounded autonomy and Caller authority.