Kafka MCP

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describe_consumer_group

Describe Kafka consumer groups to see members, assigned partitions, committed offsets, and lag, so you can identify which pod or host owns a stuck or lagging partition.

Instructions

Describe 1 to 100 consumer groups in one call through items: state, assignor, coordinator broker, every running member (member_id, client_id, host and the partitions assigned to it), and for every partition the group owns or has committed on, the committed offset, end offset, lag, and the member, client id and host consuming it. Partitions and members are sorted.

Use it to find which consumer instance owns a stuck or lagging partition, so the operator knows which pod or host to inspect. has_commit false means the group owns the partition but never committed there, so its starting point is decided by the consumer's auto.offset.reset rather than by an offset. An Empty group has no members but keeps its commits.

Results follow items order, each carrying index with result or error.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`items`	Yes	The groups to describe, 1 to 100 of them. Describing one group is an array of length one. Results follow this order and a group that does not exist is reported against its own item.

Output Schema

TableJSON Schema

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

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Oct 7, 2026

TDQS

A4/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does substantial work: it explains has_commit semantics, that an Empty group keeps its commits, that partitions/members are sorted, and that non-existent groups are reported per item. It omits permission/auth requirements and any cost concerns, keeping it from a 5.

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 core capability before usage and edge-case detail, with no filler sentences. It is dense but each sentence carries information; slight length keeps it from a 5.

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?

An output schema exists, yet the description still covers the parameter contract, per-item error reporting, and edge-case semantics. An agent has everything needed to call it correctly and interpret results.

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 single parameter is fully documented in the schema, so the baseline is 3. The description restates the items-ordering behavior that the schema already specifies, adding no new syntactic or format guidance.

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?

States a specific verb (Describe) and resource (consumer groups) and enumerates the exact fields returned (state, assignor, coordinator, members, partitions, offsets, lag), which goes well beyond the name. It does not explicitly distinguish itself from close siblings such as consumer_lag or list_consumer_groups, so it falls short of a 5.

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?

Provides a concrete use case: 'find which consumer instance owns a stuck or lagging partition, so the operator knows which pod or host to inspect.' This gives clear situational context, but it names no alternative tool or exclusion condition, so it stops short of a 5.

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