Port from nearai/ironclaw#5149 (the describe-first live-hardening fix in
their progressive tool disclosure work): when a model invokes a deferred
tool through the tool_call bridge without the schema-required arguments,
return the tool's parameter schema instead of dispatching blind.
Pre-fix, a blind call produced an opaque downstream failure
("[TOOL_ERROR] Tool execution failed: KeyError: 'document_id'") that
teaches the model nothing about what the tool expects — IronClaw observed
cheap models looping ~30 identical invalid calls until the iteration
budget died. Post-fix, the model repairs the call in one round-trip.
- tools/tool_search.py: new validate_deferred_call_args() — key-absence
check of schema 'required' fields only; no type checking (coerce_tool_args
already repairs types downstream); fails open on any validator error so
it can never block a legitimate dispatch.
- model_tools.py: probe after the scope gate in the bridge dispatch.
- agent/tool_executor.py: probe in both unwrap sites (concurrent +
sequential) before the underlying tool replaces the bridge; sequential
path flattens the payload to match its {"error": str} wrapping.
- tests: TestDeferredCallSchemaProbe — blind call returns schema (not
KeyError), valid/optional calls dispatch, unvalidatable tools fail open,
out-of-scope rejection unchanged.
Teknium review changes on the tiered policy:
1. threshold_pct default 10 -> 5 (listing budget = min(5% of context,
listing_max_tokens)); unknown-context fallback 20K -> 10K.
2. Tier 2 no longer leaves the model blind: when even names-only doesn't
fit, the bridge description now carries a one-line-per-server summary
('cloudflare (3320 tools)') plus an instruction to search FIRST rather
than substitute a generic tool or claim the capability is missing —
the measured tier-2 failure mode (core-tool substitution) at zero
meaningful token cost (~50 tokens/server).
3. Listing degradation is now PER SERVER, largest first: one oversized
server (Cloudflare) collapses to its summary line while small
co-attached servers (Linear) keep their full per-tool listings
('mixed' form). Previously global: attaching Cloudflare next to
Linear silently cost Linear its listing. Greedy fit is deterministic
(size then label) so the rendered block stays byte-stable per catalog
— prompt-prefix cache safe.
E2E on real captures (defaults, 200K ctx): linear alone -> tier 1 full;
unreal alone -> tier 2 groups (5% budget) / tier 1 names at 1M;
cloudflare alone -> tier 2 groups; linear+cloudflare -> tier 1 MIXED
(linear fully listed, cloudflare summarized). 48/48 tests.
Tier 0: no MCP/plugin tools -> everything eager (pass-through).
Tier 1: deferred tools whose catalog listing fits min(threshold_pct%
of context, listing_max_tokens) -> bridge + skills-style
listing, degrading to names-only over budget.
Tier 2: listing over budget even names-only (Cloudflare's flat API
surface: 3,320 tools, names alone ~32K tokens) -> bare bridge,
discovery through tool_search only.
The old activation threshold (defer only when schemas > threshold_pct
of context) let mid-size catalogs ride eager and pay full schema cost;
with servers like Cloudflare (~597K tokens of schema, would not even
fit a 200K window) the binary gate is the wrong shape. Activation is
now driven purely by deferrable-tool presence; threshold_pct is
repurposed as the listing budget's context-relative leg.
- AssemblyResult gains tier + listing_form for observability
- listing_max_tokens default 4000 -> 20000 (cap 60000) so an 830-tool
catalog keeps a names-only listing while Cloudflare-scale drops to
bare bridge
- E2E verified against real captures: Linear 24 tools -> tier 1 full,
Epic UE 5.8 830 tools -> tier 1 names-only, Cloudflare 3,320 tools
-> tier 2 (both 200K and 1M context)
Deferred MCP/plugin tools become invisible once the tool_search bridge
activates — live benchmarking (48 runs, Claude Haiku 4.5) showed models
substituting visible core tools (terminal/web_search/browser) for deferred
capabilities or declaring them nonexistent instead of searching: 16/24
task success vs 24/24 with eager loading.
Skills never had this failure mode because every skill keeps a ~21-token
name+description listing line in the system prompt. This ports that exact
pattern to the tool bridge: when tool_search activates, a grouped manifest
of every deferred tool (name + first sentence of description, clipped to
60 chars, grouped per MCP server / toolset) is embedded in the tool_search
bridge description.
- tools/tool_search.py: build_catalog_listing() with deterministic
ordering (byte-stable across assemblies -> prompt prefix stays
cacheable); token-budget fallbacks full -> names-only -> legacy bare
count; bridge_tool_schemas(listing=...) embeds it and instructs the
model to skip tool_search when the exact name is visible (one fewer
round-trip per use)
- config: tools.tool_search.listing auto|on|off (default auto),
listing_max_tokens (default 4000, clamped 200..20000); legacy bool
shapes keep working
- tests: 8 new tests (config parsing/clamps, short-desc clipping,
deterministic rendering, budget fallbacks, bridge embedding, assembly
on/off paths); full file green (47 passed)
- docs: tool-search.md config table + rationale
- scripts/tool_search_livetest2.py: benchmark harness v2 with real
per-call token accounting (normalize_usage spy) and a third 'listing'
mode for A/B/C comparison
Tool Search read its catalog from the global registry (get_tool_definitions
with no toolset scope = 'start with everything'), so a restricted-toolset
session — subagent, kanban worker, curated gateway session — could:
1. tool_search the entire process registry, not just its granted tools, and
2. tool_call any registered plugin/MCP tool it was never given, because
registry.dispatch() has no enabled_tools gate for non-execute_code tools.
A scoped session (enabled_toolsets=['mcp-github']) reported total_available=26
and successfully invoked an out-of-scope plugin tool via tool_call.
Fix:
- handle_function_call gains enabled_toolsets/disabled_toolsets; the bridge
dispatch scopes get_tool_definitions to them (also stops polluting the
process-global _last_resolved_tool_names with out-of-scope tools, which
leaked into execute_code's sandbox-tool fallback).
- A defense-in-depth gate rejects any tool_call'd name not in the scoped
deferrable catalog.
- tool_executor's unwrap (both concurrent + sequential paths) enforces the
same scope before dispatch, since it unwraps tool_call -> underlying name
and bypasses the bridge branch. New _tool_search_scoped_names() helper,
cached per-agent on registry generation + toolset scope.
- New scoped_deferrable_names() helper in tool_search.py shared by both sites.
Tests: 4 new regression tests in TestRegression_ToolsetScoping (scoped
catalog, out-of-scope tool_call rejection, no global pollution, helper).
Adds Tool Search, a structured-tools progressive-disclosure layer that
replaces MCP and non-core plugin tools in the model-visible tools array
with three bridge tools (tool_search / tool_describe / tool_call) when
the deferrable surface would consume more than a configurable percentage
of the active model's context window. Core Hermes tools are never deferred.
Default mode is 'auto' with a 10% context threshold, so small toolsets
pay no overhead. Set tools.tool_search.enabled to 'on' to force or 'off'
to disable.
Design carefully reflects the OpenClaw production failure modes
documented in the openclaw-tool-search-report:
- Core tools never defer (toolsets._HERMES_CORE_TOOLS). Addresses the
'tools silently missing from isolated cron turns' regression class
(openclaw#84141) by construction: there is no code path that can
drop a core tool.
- Catalog is stateless across turns — rebuilt from the live tool-defs
list on every assembly. No session-keyed Map that can drift out of
sync with the registry.
- tool_call unwraps the bridge call before any hook fires, so plugin
pre/post hooks, guardrails, approval flows, and the activity feed
all see the underlying tool name, not the bridge (addresses
openclaw#85588 and the verbose-mode complaint on openclaw#79823).
- The unwrap happens in both the parallel and sequential paths of
agent/tool_executor.py and also in handle_function_call, so direct
callers (sandboxed code, eval harnesses) are covered too.
- Bridge tools cannot invoke each other (recursion guard) and cannot
invoke core tools (those must be called directly).
- Tools mode only — no JS-sandbox code-mode. Keeps the surface small.
- Token estimation via cheap char/4 heuristic; precision isn't needed
for the threshold decision.
Files:
- tools/tool_search.py — new module (BM25 retrieval, classification,
threshold gate, bridge dispatch, unwrap helper).
- tests/tools/test_tool_search.py — 35 tests including the OpenClaw
#84141 regression guard.
- model_tools.py — wires assembly into _compute_tool_definitions as the
final step, adds skip_tool_search_assembly kwarg so the bridge can
see the real catalog, dispatches the three bridge tools.
- agent/tool_executor.py — unwraps tool_call in both parallel and
sequential parsing loops so checkpointing, guardrails, plugin hooks,
and tool-progress callbacks all observe the underlying tool name.
- hermes_cli/config.py — DEFAULT_CONFIG['tools']['tool_search'] block.
- website/docs/user-guide/features/tool-search.md — user docs.
Validation:
- 35/35 new tests pass.
- Existing tool/registry/model_tools/config/coercion/executor tests
(82 + 74 + small adjacents) green.
- Live E2E: 20 fake MCP tools registered, get_tool_definitions returns
3 bridges, tool_search returns top 3 hits, tool_describe returns
full schema, tool_call dispatches to the real underlying handler
and the underlying result is what the model sees.
- Reserved-name recursion guard verified live.
- Core-tool refusal via tool_call verified live.
