Only 29% of top MCP servers ship output schemas, scan finds
A scan of the 257 most-used MCP servers on Smithery found that while 99% include tool descriptions, only 29% ship output schemas.
Score breakdown
Composite · rank 13
6.5
out of 10
Novelty · 25%
7
Novelty
Impact · 43%
7
Impact
Credibility · 12%
6
Credibility
Depth · 20%
5
Depth
Weights applied. How scores work ↗
Why it matters
The near-universal adoption of tool descriptions contrasts sharply with the low rate of output schemas, revealing a gap in MCP server metadata that affects how reliably agents can interpret and act on tool results.
- 01257 of the most-used MCP servers on Smithery were scanned.
- 0299% of scanned servers include tool descriptions.
- 03Only 29% of scanned servers ship output schemas.
Summary— our read of the original
No summary available yet.
Key facts
- 01257 of the most-used MCP servers on Smithery were scanned.
- 0299% of scanned servers include tool descriptions.
- 03Only 29% of scanned servers ship output schemas.
Topics
Methodology
Summary and scoring are generated automatically from the original article. We always link back to the publisher and never republish images or paywalled content. Last processed Jun 18, 2026 · 10:40 UTC. How this works →