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BrightbeamAI

@brightbeamai/chap-coordinator-mcp

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Rotate signing key

chap.participant.rotate_key

Retire a participant's signing key and register its replacement, keeping the old key in history so previously signed envelopes still verify.

Instructions

Retire a participant's signing key and register its replacement. The old key stays in the key history with a valid_until timestamp, so envelopes it signed still verify.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
fromYesParticipant URI, e.g. 'human:alice@example.org' or 'agent:bot@local'.
new_jwkYesThe replacement public key as a JWK. It must carry a 'kid'. Whether the request itself has to be signed with the old key is decided at dispatch, and only where the coordinator is configured to require signatures.
old_kidYesKey id being retired. It is given a valid_until timestamp and stays in the member's key history, so signatures made before the rotation still verify. A key id that is unknown is refused with -32071, and one already revoked with -32072.
workspaceYesWorkspace identifier, e.g. 'wsp_techcorp_support'.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.2.13

TDQS

A3.8/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare non-read-only, non-destructive, non-idempotent, but the description adds real context the annotations cannot: the old key is retained in key history with a valid_until timestamp so prior signatures still verify. That materially explains why destructiveHint=false holds. The conditional signature requirement is only covered inside the new_jwk parameter, not surfaced as behavioral guidance.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with the operation front-loaded and the retention consequence second. Every clause earns its place and nothing is padded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a four-param mutation with no output schema but fully described inputs and error codes, the description covers what happens to the retired key and the replacement. It could say more about permissions/authentication needed to rotate another participant's key, which is the main remaining gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so old_kid, new_jwk, from, and workspace are already well documented, including error codes -32071/-32072 and the conditional request-signing rule. The description adds no per-parameter detail beyond what the schema provides, which is the expected baseline when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb+resource: 'Retire a participant's signing key and register its replacement' names the retire-and-replace operation precisely, and the second sentence clarifies the retained-history semantics. It never names the close sibling chap.participant.revoke_key, so the rotate-vs-revoke distinction is left for the agent to infer.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the replace semantics (rotate when you have a replacement key), and the retained-history note hints at why one would rotate rather than revoke. There is no explicit when-to-use/when-not guidance and no mention of the alternative chap.participant.revoke_key, which shares the same key-management surface.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.