Module tool_visibility 

Pure tool-visibility policy for the MCP tools/list response.

Extracted from the (async, server-bound) list_tools handler so the policy is unit-testable in isolation. The handler resolves the candidate set (lazy-core vs profile-authoritative vs full registry) and the per-call gates (role, workflow), then defers to these helpers for the stable rules:

• Internal/meta tools are never advertised.
• The active profile, disabled_tools, and the per-client ClientQuirks (Zed ctx_edit, native-editor ctx_patch) filter the candidates.
• The universal invoker (ctx_call) is force-advertised in non-full mode so tools hidden by lazy/profile filtering stay reachable.

Structs

ClientQuirks

Client-specific advertising quirks, resolved once per tools/list from the MCP clientInfo name and the candidate set.

Enums

CandidateSet

Which candidate pool tools/list starts from, before per-tool gates run.

Constants

INVOKER

The universal invoker tool name. A static-list MCP client can call any registered tool through it, even when that tool isn’t advertised.

Functions

advertised_tool_defs_default

Computes the tool set this install advertises to a default client (no client quirks, no role restriction, no workflow gate, static tool list), including the live description compression. Offline counterpart of the tools/list handler for doctor overhead / ContextOverhead::measure — kept next to the pure gates so measurement cannot drift from policy. “No quirks” is the worst case: a client without a native editor sees ctx_patch too, so the reported overhead never understates.

candidate_set

Decides the candidate pool. Single source of truth for the tools/list handler AND offline measurement (doctor overhead), so the advertised surface and the reported overhead can never drift apart.

category_gate_applies

Whether the lazy per-category gate should filter the advertised tool set.

explicit_profile

Whether the user explicitly pinned a tool profile (config key, custom tool list, or env var) — the trigger for CandidateSet::ProfileAuthoritative.

is_tool_visible

Decides whether a tool name should appear in tools/list.

mark_auto_ctx_tool_used

Mark that the agent has invoked a ctx_* MCP tool in this session.

needs_invoker

Whether INVOKER must be force-added to the advertised set.

record_auto_turn

Increment the Auto-profile turn counter (call once per tools/list request).

resolve_auto_profile

Resolve ToolProfile::Auto to a concrete profile using session signals. Non-Auto profiles are returned as-is.

set_auto_system_prompt_tokens

Update the system prompt token estimate for Auto-profile resolution.