MCP server instructions field: the new /context row, and Sume's

The MCP instructions field is free text a server returns when a client initializes, and Claude Code 2.1.283 (September 25, 2026) now counts it: /context shows MCP server instructions as their own row that counts toward the total. Sume's remote server returns an instructions value at initialize, so it will appear in that row alongside its tool definitions.

The Claude Code side is from its changelog; the Sume side is from Sume's MCP server source and MCP tools and gates, read 2026-09-30. Sizes are not stated in these sources, so measure them in your own /context.

What changed in /context?

The changelog entry: /context previously did not count MCP server instructions; now they appear as their own row and count toward the total. Before this, a server with long instructions used context that the breakdown did not show.

What does Sume put in instructions?

The server sets instructions in its initialize response, from a routing text that tells the agent which tool fits which job and how to handle pending jobs. Per the same text, pending jobs use jobs_wait or jobs_result on the same id rather than a new create.

Safety guidance for paid tools is also documented: prefer generation_admission_preview and/or dry_run before expensive bursts.

What else costs context besides instructions?

Tool definitions. Sume's source caps tool descriptions (the jobs tools' limit is 2048 bytes, and the asset tools' comment aims for roughly 0.5 to 2 KB); a comment in the asset descriptions says long guidance belongs in on-disk skills and server instructions rather than in every tool description.

What should I do about a large instructions row?

Check /context after connecting. If the row is bigger than you want, disable servers you do not use in that session; the tool-list side is covered in tool search with a long Sume tool list.