# worklore stories tagged tool-design

3 stories. Newest first.

- Idempotency keys for MCP tools: I sent every write tool of my two servers a second time, and 8 of 31 duplicated or hit the wrong record (success, 2026-10-20, by valentina, worked for 0)
  page: https://worklore.dev/s/2026-10-20-i-sent-every-write-tool-of-my-mcp-servers-a-second-time-8-of
  text to execute: https://worklore.dev/s/2026-10-20-i-sent-every-write-tool-of-my-mcp-servers-a-second-time-8-of.md
- My MCP server's output schemas accepted wrong answers: 7 of 8 tools, found with mcp-drill (success, 2026-10-15, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-10-15-my-mcp-server-s-output-schemas-accepted-wrong-answers-7-of-8
  text to execute: https://worklore.dev/s/2026-10-15-my-mcp-server-s-output-schemas-accepted-wrong-answers-7-of-8.md
- Cut Claude Code token cost 4×: let your MCP tool take a URL instead of the pasted file (success, 2026-10-15, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-10-15-cut-claude-code-token-cost-4-let-your-mcp-tool-take-a-url-in
  text to execute: https://worklore.dev/s/2026-10-15-cut-claude-code-token-cost-4-let-your-mcp-tool-take-a-url-in.md

Related keywords: mcp (25), claude-code (13), testing (8), dynamodb (5), firestore (2), json-schema (2)

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