analyze-agent-loop

A method for tracing how an AI agent receives a request, processes it, calls tools, waits for results, and produces a response. It also maps the agent’s states, saved information, and stopping conditions.

In plain words
What is it for?
Use it to inspect an agent’s runtime flow, document its execution cycle, analyze state changes, and find how tool calls continue or end.
Why use it?
It makes complex request handling easier to understand and helps reveal where loops, tool continuations, or state transitions go wrong.

Skill for Claude CodeCodex

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 skills/quangphu1912/codebase-analyzer/analyze-agent-loop
Any agent
npx skills add quangphu1912/codebase-analyzer --skill analyze-agent-loop
Clone the repo
git clone --depth 1 https://github.com/quangphu1912/codebase-analyzer

Made for: Claude Code, Codex.

Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,302 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 $0.00034 $0.01302
Opus 5 $0.00017 $0.00651
Sonnet 5 $0.00007 $0.00260
Haiku 4.5 $0.00003 $0.00130

Measured 2d ago against content hash 3102bc750c8f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

analyze-agent-loop 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 2d ago.

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.

skills/analyze-agent-loop/SKILL.md · 132 lines

How it starts

The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Announce at start: "Using codebase-analyzer to analyze the agent loop."

Overview

Map the runtime execution spine: how does a request enter, get processed, and produce output? Identify the turn loop, state machine, and tool continuation patterns.

Prerequisite: Reads docs/analysis/artifact-classification.md (need to know core vs support).

Process

  1. Identify the main entry point and request handler
  2. Trace the turn/request loop: input -> processing -> tool call -> response -> next turn
  3. Map state transitions: idle -> active -> waiting -> responding -> idle
  4. Find tool continuation patterns: when does the system call another tool after receiving output?
  5. Identify termination conditions: when does the loop stop?
  6. Find state persistence: what survives between turns?
  7. Produce execution spine diagram

State Machine Decomposition

Break the agent loop into discrete states and map every transition between them. The canonical state cycle is:

IDLE -> RECEIVING -> PROCESSING -> TOOL_CALL -> WAITING -> RESPONDING -> IDLE

For each state, identify:

  • Entry condition -- what causes the system to enter this state?
  • Actions -- what work happens while in this state?
  • Exit transitions -- what are the possible next states, and what triggers each?
  • Error paths -- what happens on failure within this state?
State Transitions:
  IDLE        --[new message]-->  RECEIVING
  RECEIVING   --[parsed]-->       PROCESSING
  PROCESSING  --[tool needed]-->  TOOL_CALL
  PROCESSING  --[text reply]-->   RESPONDING
  PROCESSING  --[error]-->        ERROR
  TOOL_CALL   --[dispatched]-->   WAITING
  WAITING     --[tool result]-->  PROCESSING (continuation)
  WAITING     --[timeout]-->      ERROR
  RESPONDING  --[sent]-->         IDLE
  ERROR       --[retry]-->        RECEIVING
  ERROR       --[fatal]-->        IDLE (terminal)

Look for states that are implicit rather than explicit -- code that behaves like a state machine without naming states is harder to debug. Identify any states not covered by the canonical cycle (e.g., RATE_LIMITED, CANCELLED, STREAMING).

Read the full file on GitHub · 132 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 132 lines · 34 tokens per session scan A 3102bc750c8f

Subscribe to this mod's changes

analyze-agent-loop is a skill published in the GitHub repository quangphu1912/codebase-analyzer (2 stars, last pushed 4mo ago), licensed MIT. It adds 34 tokens to every session and 1,302 once invoked, about $0.0002 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 2026-08-31.