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delete_consumer_group

Delete up to 1,000 consumer groups and their committed offsets to stop decommissioned consumers from reporting undrainable lag. Preview the batch first; active groups are refused.

Instructions

Delete 1 to 1000 consumer groups in one call through items, removing each group's committed offsets. Use it to clean up groups whose consumers were decommissioned: their commits keep reporting lag that nobody will ever drain. Deleting one group is an items array of length one.

No group is deleted unless confirm is true. The preview lists each group's state, the topics it has committed on, every committed offset with its lag, and the total lag that would disappear with it. A group with active members is refused: it is not abandoned, and deleting it would reset where its consumers resume.

If a consumer later starts with the same group id, it begins wherever its auto.offset.reset points, not where the group left off. One confirm covers the whole batch, and deletion is not atomic: groups deleted before a later item failed stay deleted. Results follow items order, each carrying index with result or error. Requires Kafka DELETE permission on the group.

Input Schema

Name	Required	Description	Default
`items`	Yes	The groups to delete, 1 to 1000 of them. Deleting one group is an array of length one. Naming the same group twice is refused before anything is deleted.
`confirm`	No	Optional. When false or omitted, nothing is deleted and the response shows each group's committed offsets and lag. Must be true to delete. One confirm covers the whole batch.

Output Schema

Name	Required	Description	Default
`atomic`	Yes
`failed`	Yes
`applied`	Yes
`results`	Yes
`succeeded`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.2.7Oct 25, 2026

changedInput schema / properties / items / description

Previous value: -"The groups to delete, 1 to 100 of them. Deleting one group is an array of length one. Naming the same group twice is refused before anything is deleted."New value: +"The groups to delete, 1 to 1000 of them. Deleting one group is an array of length one. Naming the same group twice is refused before anything is deleted."

First observedv0.2.0Oct 7, 2026

TDQS

A4.4/5.0

Behavior5/5

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

With no annotations, the description carries the full burden and does: confirm-gated preview, refusal of groups with active members, offset reset behavior for a reused group id, batch-level confirm, non-atomic partial failure, ordered per-item results, and the required Kafka DELETE permission. These are exactly the consequences an agent needs before calling a destructive tool.

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

Conciseness4/5

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

Front-loaded with the action and the cancel-by-default confirm gate, then each subsequent paragraph earns its place by covering preview contents, refusal, consequences, and partial-failure ordering. It runs long for a tool description, but there is almost no filler.

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

Completeness5/5

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

The output schema covers the per-item index/result/error shape, and the description covers everything else an agent needs: batch limit, confirm gate, preview payload, refusal conditions, non-atomicity, and permissions. Nothing material is left for the agent to guess.

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 coverage is 100% and the schema already documents items, the one-group-as-array-of-one convention, duplicate-name refusal, and confirm semantics. The description restates those rather than adding new meaning such as validation rules, size limits per item, or error formats not in the schema, so baseline 3 applies.

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

Purpose5/5

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

States a specific verb and resource (delete consumer groups), the scope (1–1000 per call via items), and the concrete side effect (committed offsets removed). It also disambiguates from sibling operations like describe_consumer_group or consumer_lag by framing this as the cleanup path for abandoned groups.

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

Usage Guidelines4/5

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

It gives a clear when-to-use condition — decommissioned consumers whose stale commits report lag that will never drain — and a when-not case (groups with active members are refused). It does not name a sibling alternative such as resetting offsets or describing the group first, so usage routing is inferred rather than explicit.

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