Registry › Compare › A2A / Agent2Agent Protocol vs MCP Inspector

A2A / Agent2Agent Protocol vs MCP Inspector

Both are Grade A and 2.2 points apart, so choose on what you weigh most. A2A / Agent2Agent Protocol leads on supply-chain integrity and adoption, and rests on broader evidence; MCP Inspector leads on maintenance. Note: MCP Inspector's evidence coverage is thinner (coverage B vs A) — its score rests on fewer independent signal types.

A A2A / Agent2Agent Protocol 89.4

Agent2Agent (A2A) is an open protocol enabling communication and interoperability between opaque agentic applications.

a2aproject/A2A · #30 overall · #4 Protocols & Tool Integration · coverage A (4/5)

Choose A2A / Agent2Agent Protocol if supply-chain integrity and adoption matter most.

+3.0Safety / Integrity: 100% of recent commits signed, against 32%
+2.0Adoption: 2.8M weekly downloads against 399.3k
A vs BEvidence coverage: 4 of 5 independent signal types, against 3

A MCP Inspector 91.6

Visual testing tool for MCP servers

modelcontextprotocol/inspector · #14 overall · #3 Protocols & Tool Integration · coverage B (3/5)

Choose MCP Inspector if maintenance matters most.

+2.7Maintenance

Where they differ

21.2

Safety / IntegrityA2A / Agent2Agent Protocol +3.0

18.2

14.4

TransparencyMCP Inspector +0.3

14.7

17.2

MaintenanceMCP Inspector +2.7

19.9

19.2

AdoptionA2A / Agent2Agent Protocol +2.0

17.2

-0.6

Runtime calibrationMCP Inspector +4.2

+3.6

1 dimension identical: Identity 18.0 · Full evidence table

An independent, evidence-based trust comparison of A2A / Agent2Agent Protocol and MCP Inspector, two Protocols & Tool Integration projects in the HVTracker registry. Scores come from public, checkable signals — supply-chain provenance, OSSF Scorecard, maintenance, and adoption — not popularity.

Full evidence

Signal	A2A / Agent2Agent Protocola2aproject/A2A	MCP Inspectormodelcontextprotocol/inspector
HVTrust score	89.4	91.6
Evidence grade	A	A
Coverage grade	A	B
Overall rank	#30	#14
Rank in Protocols & Tool Integration	#4	#3
GitHub stars	26.1k	11.1k
Last updated	1d ago	1d ago
Build provenance	Yes	Yes
OSSF Scorecard	7.0 / 10	7.3 / 10
License	Apache-2.0	NOASSERTION
Downloads	2.8M/wk	399k/wk
Trust dimensions (points earned)
Safety / integrity / 25	21.2	18.2
Identity & provenance / 18	18.0	18.0
Transparency / 17	14.4	14.7
Maintenance / 20	17.2	19.9
Adoption / 20	19.2	17.2
Runtime capability surface (full matrix)
MCP server	—	Implemented
External providers	—	—
Requires API keys	No	No
Plugin surface	extensions	—
Provenance drift	Unknown	Match

Open in the live compare tool → A2A / Agent2Agent Protocol profile MCP Inspector profile More Protocols & Tool Integration →

How to read this: HVTrust (0–100) weighs supply-chain signals (provenance, OSSF Scorecard, signed commits, open license) alongside real-world adoption, scaled by an evidence-confidence factor. Grade bands: A ≥ 80, B ≥ 65, C ≥ 50, D < 50. Signals refresh daily. Full methodology v4.4 →