alkhttp/tasks/adapters/review-002-mcp-batch-cap.md

id, name, status, depends_on, scope, risk, impact, level, tags

id	name	status	depends_on	scope	risk	impact	level	tags
review-002-mcp-batch-cap	Cap MCP batch tool at MAX_BATCH_OPERATIONS (PRJ-22)	completed		single	low	component	implementation	adapters review-002 mcp

Description

Review 002 PRJ-22 [minor]. The MCP batch tool has no cap on the calls array (to_mcp.rs:215-247 executes serially) while HTTP /batch rejects at 101 (routes.rs:173-184, MAX_BATCH_OPERATIONS). A 10,000-entry MCP batch occupies the dispatch spine serially (each invoke up to the 30 s deadline) — the doc (PRJ-09's fix) advertises no limit either.

Acceptance Criteria

• The batch tool enforces the same MAX_BATCH_OPERATIONS cap (share the constant; do not duplicate the literal) — over-cap → structured INVALID_INPUT-family error consistent with the tool's other argument errors (including retryable, per PRJ-13)
• Tool description states the limit (mirroring how /batch docs it) — ADR-041 shape unchanged (4 fixed tools)
• Test: over-cap calls array → structured error, no dispatch happened (spy/gateway-count assert via the existing invoke_tool harness)
• cargo test --features mcp, cargo clippy --all-features --all-targets -- -D warnings, cargo fmt --check pass

References

• docs/reviews/002-post-remediation-review.md (Part F', PRJ-22)
• src/adapters/to_mcp.rs:215-247 (the loop), src/gateway/routes.rs:42,173-184 (the cap to share)
• tasks/adapters/review-001-mcp-tool-fidelity.md (the PRJ-07..10/13 work whose conventions to follow)

Notes

One of the smallest tasks in the batch — a good first warm-up slice or fold-in candidate if a session runs short (but keep the commit separate; it is its own unit of work).

Summary

MAX_BATCH_OPERATIONS hoisted to gateway/mod.rs (shared by routes/to_mcp/to_openapi); MCP batch rejects >100 calls pre-dispatch with INVALID_INPUT; schema maxItems + tool description updated. GatewayDispatch::invoke_count() test-spy accessor added.