P7: Bounded, High-Signal Responses

Definition

CLI tools MUST provide mechanisms to control output volume. Agent context windows are finite and expensive: a tool that dumps tens of thousands of lines of unfiltered output wastes tokens on every request and can exceed smaller context windows entirely, breaking the conversation that invoked it. "High-signal" here means the bytes that survive --quiet are the ones the caller asked for (data and errors), not progress, decoration, or chatter.

Why Agents Need It

Unbounded CLI output is expensive for any agent: token cost and context-window capacity for LLM agents, parse cost and memory pressure for scripts, schedulers, and other automation. Either way, the agent ends up truncating (losing potentially important data) or consuming the full response (wasting cycles on noise). Bounded output with --quiet, --verbose, and --limit flags gives the agent precise control over how much data arrives, keeping responses high-signal and inside budget.

Requirements

MUST:

A --quiet flag suppresses non-essential output: progress indicators, informational messages, decorative formatting. When --quiet is set, only requested data and errors appear. Implementations route diagnostics through a macro that short-circuits when quiet is on:
```
macro_rules! diag {
    ($cfg:expr, $($arg:tt)*) => {
        if !$cfg.quiet { eprintln!($($arg)*); }
    }
}
```
(Applies when: CLI has list-style commands.) List operations clamp to a documented default maximum. A list without --limit does not return more than a configurable ceiling (e.g., 100 items), and that ceiling is named in --help so callers can plan around it. If more items exist, the output indicates truncation: "truncated": true in JSON, a stderr note in text mode.

Evidence

A --quiet flag that respects both CLI and environment-variable input, with explicit override semantics (e.g., --quiet=false beats QUIET=1).
A diagnostic macro (or equivalent gate) that short-circuits when quiet is true.
--limit or --max-results on every list / search command.
Pagination clamping logic (e.g., min(requested, MAX_RESULTS)).
--timeout flag with a sensible default.
--verbose flag for diagnostic escalation.
A suppress_diag() method that returns true when quiet is set or when the output format is JSON / JSONL.

Anti-Patterns

List commands that return all results with no default limit: an agent listing 50,000 items floods its context window.
No --quiet flag: agents consuming JSON output still receive interleaved diagnostic text on stderr.
--verbose as the only output control. If there is no way to reduce output, bounded responses do not exist.
Progress bars or spinners that write to stderr in non-TTY contexts, adding noise to agent logs.
No --timeout on network operations. A stalled request blocks the agent indefinitely.

Measured by audit IDs p7-quiet, p7-limit, p7-timeout. Run anc audit --principle 7 . against the CLI under test to see each.