version: "1.0.1" name: decompiler-mcp description: Use when working with the DecompilerServer MCP server to inspect, search, decompile, analyze, or compare .NET assemblies, especially foreign code such as Unity/RimWorld assemblies, third-party DLLs, game binaries, or version-to-version assembly diffs. Prefer this skill when choosing the right DecompilerServer tool sequence and avoiding premature shell fallbacks.

DecompilerServer MCP

Use DecompilerServer as the primary source of truth for loaded .NET assemblies. Do not guess member IDs or fall back to shell scans after one failed symbol lookup; use the discovery and diagnostic tools first.

Default Workflow

1. Load or confirm context:

• load_assembly with assemblyPath, or gameDir plus assemblyFile for Unity layouts.
• status for readiness and the current context. Use list_contexts(includeRegistered: true, limit, cursor, filter) only to discover registered aliases. Passing contextAlias activates a registered alias on demand.
• Use get_server_stats only when cache, index, or performance diagnostics matter.

1. Discover symbols:

• Use search_symbols first for fragments or when unsure whether a name is a type or member.
• Use resolve_member_id first for fully-qualified or XML-doc-like guesses such as Namespace.Type.Member, Namespace.Type:Member, or M:Namespace.Type.Member.
• Use search_types when looking only for types.
• Use search_members when looking only for methods, fields, properties, or events.

1. Inspect type surface:

• Use list_members after resolving a type (get_members_of_type is its compatibility alias).
• Prefer mode: "signatures" for orientation and mode: "full" only when extra metadata is needed.
• Generated members and accessors are hidden by default; use includeCompilerGenerated: true when those are the subject of inspection.

1. Read code:

• Use get_decompiled_source for complete focused source.
• Use plan_chunking and get_source_slice for large types or methods.
• Batch source defaults to 50 lines per member (maxLinesPerMember). Partial entries have hasMore and nextStartLine; continue with a source slice. Outer truncated includes partial members; budgetTruncated specifically means the total character cap was reached.

1. Analyze relationships:

• Use find_callers, find_callees, and find_usages for call/use questions.
• Callers/usages default to scope: "assembly"; use scope: "workspace" for all currently loaded contexts. Inspect searchedContexts; deferred aliases are not activated by that query.
• Callees link exact members in other loaded contexts with resolution: "workspace"; external targets retain referenced assembly identity.
• Use find_base_types, find_derived_types, get_overrides, and get_implementations for inheritance questions.
• Type metadata outlines have addressable child IDs and limit/cursor paging; maxDepth: 0 omits children, and larger values show the direct member level.
• Use get_il before proposing transpiler anchors; suggest_transpiler_targets should be treated as a real-IL hint list, not a substitute for reading IL.

1. Compare versions:

• Use compare_contexts for structural alias-level overview.
• Use compare_symbols for type/member drill-down.
• Use compare_symbols with compareMode: "body" only for method bodies.

Recovery Rules

• If it returns context_not_loaded or member_context_mismatch, follow the assembly-loading hint and retry the canonical ID in its owning context. Do not search the MVID or kind suffix as a symbol.
• If it returns ambiguous_member, choose a candidate ID or supply the parameter types.
• If a member-based tool returns type_not_found, call search_types or search_symbols with the type fragment.
• If it returns member_not_found, inspect error.details.candidates and call the suggested get_members_of_type or search_symbols.
• If search_symbols returns diagnostic.code: "member_guess_unresolved", the type resolved but the member guess did not; inspect the returned direct members or call the suggested list_members.
• If it returns wrong_symbol_kind, switch to the tool for the actual kind instead of retrying the same call.
• If a memberId contains an MVID, follow-up calls normally do not need contextAlias.
• Use explicit contextAlias when working from human-entered symbols or when multiple versions are loaded and no canonical memberId has been resolved yet.

Tool Choice Bias

• Output is compact by default. Complete source is in data.code; omitted source language means C#. Source slices retain startLine, endLine, and totalLines. Use structured IL instructions, and use error.details/error.hints for recovery. Ordinary member summaries identify symbols with declaringType + name; type summaries retain fullName.
• Extended output is a user startup configuration (DECOMPILER_RESPONSE_MODE=extended), not a tool argument or an agent-controlled setting.

• search_symbols beats broad shell search for unknown names.
• resolve_member_id beats search_symbols for fully-qualified stale method guesses because its errors return typed candidates.
• list_members beats guessing conventional method names.
• get_source_slice beats dumping huge source into context when line ranges are enough.
• get_il beats external IL tools for first-pass opcode inspection; use limit/cursor or startOffset/endOffset for large methods.
• find_callees returns callee-shaped fields. Prefer targetMemberId, symbol, opcode, offset, and resolution over legacy inMember/inType aliases.
• Shell tools are a last resort for files outside loaded assemblies or for validating packaging/runtime environment, not for ordinary symbol exploration.