Tools & Connections
Function calling, MCP, APIs, browser and computer use.
24 posts · showing 11–20
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Handing an Agent a PDF: Three Paths Into the Context
A PDF never enters a context window — something derived from it does. The counterparty name right and the date wrong usually means the document took the wrong path in.
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The Timeout That Looked Like an Empty Result
The health check timed out, the handler returned an empty list, and the agent reported all clear while two services were down. An empty result and a failed check must not share a shape.
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Raw SQL or Curated Queries? Giving an Agent Your Database
A two-line tool description can hand an agent unbounded access to your data and your query planner. The guardrails matter more than the choice — and one cheap planner call prevents most of the damage.
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Computer Use: When the Agent Drives a Whole Desktop
Clicking is easy; knowing what to click is a perception problem solved from a screenshot. The failures are modals, focus loss, and scroll state — and an agent that assumes its click landed compounds errors silently.
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Retry Semantics: Which Tools Are Safe to Call Twice
Agents repeat tool calls for at least five ordinary reasons — none of them bugs. Whether that's harmless or a duplicate charge is a property of the tool, and usually one nobody wrote down.
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Designing Tools for Agents vs Designing APIs for Developers
One endpoint, one tool is the obvious mapping and the wrong one. APIs assume a consumer who reads docs once and writes a loop — an agent re-decides everything from a paragraph, every call.
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The File System as a Tool: Underrated Agent Infrastructure
Four hundred thousand rows won't fit in a context window; a path and a preview cost nothing. A scoped directory solves large results, durable state, and reviewable artifacts at once — if you resolve paths correctly.
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OAuth for Agents: Acting on Behalf of a User
A service account with everyone's access puts your entire access-control model inside a model's judgment. Per-user tokens move the check to where prompt injection can't reach it.
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Agents That Wait: Callbacks, Webhooks, and Long-Running Tools
A twenty-minute export breaks the assumption that tools return quickly. Handles, in-loop polling, and true suspension — plus the expiry field that stops suspended runs leaking forever.
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MCP: What a Standard Tool Protocol Changes, and What It Doesn't
Portable integrations and runtime discovery are real wins. Tool design, selection accuracy, permissions, and untrusted content are exactly as hard as before — and easy connection quietly makes two of them worse.