Browser MCP snapshots can cost 77,000 tokens per page load, developer finds

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A developer measured the token cost of browser-based MCP tool calls used by AI agents and found the overhead to be far higher than expected. Loading a single Hacker News comment page via a full snapshot tool consumed around 77,000 tokens, compared to just 2,700 tokens with a leaner approach. The difference stems from the accessibility tree returned on every page look, forcing the model to process large amounts of markup it does not need. Across five live tasks, the leaner method completed work roughly 3.5 times faster, finishing in about 24 seconds versus 83 seconds. The issue primarily affects setups where the client communicates only via MCP, such as Claude Desktop, and does not apply when a shell or disk-based output is available.

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