agent-as-function-tool

A compatibility reference for using one AI agent as a narrowly scoped function inside another agent. The original tutorial now points to broader documentation about function tools.

In plain words
What is it for?
Use it to find guidance and examples for delegating a bounded task, while keeping retries, fallback decisions, and approvals under the main agent's control.
Why use it?
It helps readers understand when delegation should stay small and when a larger workflow is more appropriate. The file mainly preserves existing links to the older tutorial.

Agent for Codex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/managedcode/prompterone/agent-as-function-tool
Clone the repo
git clone --depth 1 https://github.com/managedcode/PrompterOne

Made for: Codex.

Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 391 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00018 $0.00391
Opus 5 $0.00009 $0.00196
Sonnet 5 $0.00004 $0.00078
Haiku 4.5 $0.00002 $0.00039

Measured yesterday against content hash 76ce877f15e0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agent-as-function-tool scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.codex/skills/dotnet-microsoft-agent-framework/references/official-docs/tutorials/agents/agent-as-function-tool.md · 50 lines

What it actually says

Using an agent as a function tool

[!NOTE] The live Learn URL for this old tutorial now redirects to the canonical Function Tools article. Keep this local file only as a compatibility alias for existing references inside the skill catalog.

::: zone pivot="programming-language-csharp"

Use AIAgent.AsAIFunction() when one agent needs a bounded specialist capability without escalating to a full workflow.

Current guidance

  • keep the delegated behavior narrow and easy to reason about
  • keep the outer agent in control of retries, fallbacks, and policy
  • escalate to explicit workflows when control flow, approvals, or fan-out logic become important
AIAgent coordinator = chatClient.AsAIAgent(
    instructions: "Delegate weather questions when needed.",
    tools: [weatherAgent.AsAIFunction()]);

For current runnable examples, load:

  • references/official-docs/tutorials/agents/function-tools.md
  • references/official-docs/user-guide/agents/agent-tools.md

::: zone-end ::: zone pivot="programming-language-python"

The live alias now resolves to the broader Function Tools article. Use the canonical live docs for current Python examples.

::: zone-end

Next steps

  • Use references/official-docs/tutorials/agents/agent-as-mcp-tool.md when the delegated capability should surface as an MCP tool instead of a normal function tool.
  • Escalate to references/workflows.md when delegation becomes explicit orchestration instead of bounded tool composition.
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 50 lines · 18 tokens per session scan A 76ce877f15e0

Subscribe to this mod's changes

agent-as-function-tool is an agent published in the GitHub repository managedcode/PrompterOne (42 stars, last pushed 3mo ago), licensed MIT. It adds 18 tokens to every session and 391 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other agents, from other repositories

se-technical-writer

Technical writing specialist. Use PROACTIVELY to create or update developer documentation under docs/ when new features are implemented or implementation details need documenting. Produces guides, tutorials, ADRs, and reference docs.

Andes-Software-Solutions/Andes.Extensions.AI · 48 tokens

release-manager

Owns the end-to-end modelcontextprotocol/csharp-sdk release process, orchestrating the prepare-release and publish-release skills (and the bump-version and breaking-changes skills they build on) across five stages: prepare (assess SemVer, bump the version, run ApiCompat/ApiDiff, review docs, draft release notes, open…

modelcontextprotocol/csharp-sdk · 317 tokens

wpf-data-binding-expert

WPF data binding specialist. Implements complex bindings (MultiBinding, PriorityBinding), custom converters, validation patterns, and debugging binding issues.

christian289/dotnet-with-claudecode · 34 tokens

wpf-control-designer

WPF CustomControl design and implementation specialist. Defines DependencyProperty, implements Parts and States Model, OnApplyTemplate patterns.

christian289/dotnet-with-claudecode · 30 tokens

serena-initializer

Serena MCP initialization agent. Checks if current project is activated and onboarded in Serena, performs activation and onboarding if not completed. Use when starting work on a new project or when Serena tools fail.

christian289/dotnet-with-claudecode · 46 tokens

theme-slot-auditor

Read-only auditor for Fluence.Wpf theming structure. Use after any theme, brush, color, accent, or ApplicationThemeManager change to verify the three-slot MergedDictionaries invariant, that slot [0] is rebuilt and replaced every Apply, DynamicResource usage, BrushFactory auto-twinning, canonical WinUI key names, and…

sintaxasn/Fluence.Wpf · 90 tokens