Why AURA Scratchpad Is Rad: Bound the AI SRE Agent Context Window

Mezmo

Aug 20, 2026

A big tool result does not have to be a big context cost. AURA moves it to disk and hands the model a pointer plus the tools to navigate what is there.

Learn more about AURA → https://www.mezmo.com/aura
Get started today → https://github.com/mezmo/aura
Get deployment help → https://www.mezmo.com/contact

Scratchpad docs → https://docs.mezmo.com/aura/scratchpad

A large MCP tool result can consume or overflow an agent's context window, and on a third-party server you do not control how much comes back. Scratchpad breaks the link between how big a tool result is and how much context it costs: the full output goes to disk, and only the slice the model asks for ever enters the window. Errors always pass through inline, so the model can react to them.

Every tool result is token counted with the tokenizer matched to your model, and interception fires at the threshold you set for that tool. Eight structure-aware exploration tools do the reading: schema maps keys and types to line ranges, item_schema finds every field across an array, iterate_over works like a select statement over the items, and get_in, grep, head, and slice handle targeted extraction. A large markdown report buried inside a JSON string is pulled into its own companion file, with sections mapped to line ranges the model can slice.

Extraction is capped too. Every request is token counted against a per-call cap and the remaining window before it runs, and an oversized one is refused with suggestions to narrow the range, paginate, or request fewer fields. That costs one turn instead of a guessing spiral.

Setup is two additions to your TOML: enabled = true under agent.scratchpad, and per-tool thresholds on the MCP server. Thresholds are glob patterns and the most specific one wins. Turn it on for tools that can return unbounded output, such as log queries and list-everything endpoints, and skip small bounded tools where interception is pure overhead. AURA reports tokens intercepted versus tokens extracted in the CLI and emits token usage in SSE events.

AURA Scratchpad is built for SRE and platform engineers who need an agent to work against MCP servers they do not control, without a single oversized tool result deciding how much context is left.

The demo at the end runs a root cause analysis over the last five minutes to show Scratchpad working, not to reach a finding: no cause is named on camera, and AURA reports rather than acts in this video. What it does show is thousands of tokens intercepted on one run, with the speaker noting that not every run reduces consumption that sharply.

For more detail, visit
https://www.mezmo.com/videos/why-aura-scratchpad-is-rad-bound-your-agent-context-window

0:00 Why a big tool result costs the context window

0:13 What Scratchpad does

0:30 Token counting and per-tool thresholds

0:48 Eight structure-aware exploration tools

1:12 Structured strings become companion files

1:27 Capping extraction against the context budget

1:48 Tokenizer support by provider

1:58 Which tools to enable it on

2:17 Tokens intercepted versus tokens extracted

2:30 Two additions to your TOML

2:44 Running it live