| name | centrality |
| description | Rank symbols by importance — PageRank, betweenness, fan-in/out, hub detection, top-file diagnostics. |
| allowed-tools | ["mcp__mycelium__rank_symbols","mcp__mycelium__get_top_files","mcp__mycelium__get_most_connected","mcp__mycelium__get_hub_symbols","mcp__mycelium__get_fan_out_rank","mcp__mycelium__get_fan_in_rank","mcp__mycelium__get_betweenness_centrality","mcp__mycelium__get_closeness_centrality","mcp__mycelium__get_degree_centrality","mcp__mycelium__get_clustering_coefficient","mcp__mycelium__get_eccentricity","mcp__mycelium__page_rank","mcp__mycelium__get_harmonic_centrality","mcp__mycelium__get_neighbor_similarity"] |
| category | analysis |
| icon | ⭐ |
| marketplace_examples | [{"query":"Which symbols are most critical to this codebase?","tool":"mcp__mycelium__rank_symbols"},{"query":"What are the top 10 most-connected files?","tool":"mcp__mycelium__get_top_files"},{"query":"Rank all functions by fan-in","tool":"mcp__mycelium__get_fan_in_rank"}] |
centrality — who matters in this codebase
This Skill bundles 14 ranking and importance-scoring tools. Where call-graph and reachability answer "what's connected to what", centrality answers "which of those connections matter most".
Includes rank_symbols and get_top_files — two of the top-10 most useful tools per the v0.1.1 external evaluation.
When to invoke this Skill
Use when:
- The user asks "what are the most important symbols in this codebase", "which files do I need to know first", "where are the hubs".
- Onboarding into an unfamiliar project — surface the top-ranked files and symbols first.
- Identifying refactor pressure points — high-betweenness symbols are bottlenecks.
Do NOT use when:
- The user wants raw connectivity, not scores → use
call-graph or reachability.
- The user wants a specific symbol's neighborhood → use
get_symbol_neighborhood from reachability.
Quick examples
| Developer question | Tool |
|---|
| "Which symbols are most critical to this codebase?" | mcp__mycelium__rank_symbols |
| "What are the top 10 most-connected files?" | mcp__mycelium__get_top_files |
| "Rank all functions by fan-in" | mcp__mycelium__get_fan_in_rank |
| "Compute PageRank for this codebase" | mcp__mycelium__page_rank |
| "Find hub symbols with high in-degree" | mcp__mycelium__get_hub_symbols |
Capabilities under this umbrella
rank_symbols ⭐ — overall importance ranking
The single most-recommended tool for "what should I look at first" in any codebase. Combines centrality scores into one ranking.
mcp__mycelium__rank_symbols({ "limit": 20 })
get_top_files ⭐ — most important files
Same idea, file-level. Surfaces the highest-leverage files for onboarding or audit.
mcp__mycelium__get_top_files({ "limit": 10 })
Caveat: a file appearing here may be a "god file" — high importance can mean high coupling, which is often a smell.
get_most_connected — total-degree ranking
Symbols with the most edges across all kinds. Closely related to degree_centrality but conveniently sorted descending and limited.
get_hub_symbols — high in-degree
Symbols that everyone depends on. Reverse of get_dead_symbols from call-graph. Combine with get_top_files to find the load-bearing parts of the codebase.
get_fan_out_rank — symbols that call many things
Useful for "what's the most coupling-heavy code" — high fan-out often means a coordinator or orchestrator. Sometimes a refactor target.
get_fan_in_rank — symbols that many things call
Inverse of fan-out. Symbols here are the most leveraged — changes break the most callers.
betweenness_centrality — bottleneck detection
Returns the number of shortest paths passing through each symbol. High betweenness = bottleneck; if it breaks, many flows are disrupted.
mcp__mycelium__betweenness_centrality({ "edge_kind": "calls", "limit": 20 })
Expensive on large graphs — see #153 for performance bounds.
closeness_centrality — distance from everything
Symbols with low average distance to every other symbol. The "well-connected" middle of the graph.
degree_centrality — raw in/out degree
The simplest centrality. Often a good first pass before reaching for more expensive measures.
clustering_coefficient — local triangle density
How tightly clustered is a symbol's neighborhood? High = cohesive module; low = bridge.
eccentricity — farthest distance to any other symbol
The maximum shortest-path distance from the symbol to any other. Eccentricity is high for symbols "on the edge" of the call graph.
page_rank — PageRank with edge kinds
Classic PageRank, edge-kind-parameterized. Heavier than degree_centrality but more informative for asymmetric graphs.
Expensive on large graphs — see #153.
harmonic_centrality — robust closeness
Closeness centrality variant that gracefully handles disconnected graphs. Use this instead of closeness_centrality if the project has unreachable subgraphs.
neighbor_similarity — find related symbols
Given a symbol, returns symbols with overlapping neighborhoods. Useful for "find me other things like this".
Common chains
- "Where do I start understanding this codebase?" →
get_top_files then rank_symbols.
- "Where will breakage cascade if I change something?" →
get_fan_in_rank (downstream blast) + betweenness_centrality (cross-cut bottlenecks).
- "Find similar code" →
neighbor_similarity.
Performance notes
page_rank, betweenness_centrality, wcc-class algorithms are heavy on large graphs. Issue #153 tracks this; v0.1.4 introduces partial-result envelopes and a time_budget_ms parameter.
Equivalent CLI
mycelium rank-symbols --limit 20 --format=json
mycelium rank-symbols --edge-kind imports --limit 20
mycelium rank-symbols --edge-kind extends --limit 10
mycelium get-top-files --limit 10
mycelium page-rank --edge-kind calls --limit 20
Parity contract
Per RFC-0090. tests/parity.test.json asserts byte-equality on a small fixture for each capability.
Cross-references
- Related Skill:
call-graph, reachability — for the connectivity these tools rank.
- Related Skill:
graph-structure (planned) — for cycle and SCC detection that often combines with centrality.
