io.github.AIops-tools/ceph-aiops

set_pool_pg_num

Destructive

Set a Ceph pool's placement-group count (pg_num) to meet capacity or performance needs; revert to the prior count if necessary.

Instructions

[WRITE][risk=medium] Set a pool's pg_num. Reversible → prior pg_num.

Args: pool_name: Pool name (from pool_ls). pg_num: New placement-group count. target: Ceph target name from config; omit for the default.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "pool_name": "<pool_name>",
      "pg_num": "<pg_num>"
    },
    "name": "set_pool_pg_num"
  }
}

Input Schema

Name	Required	Description	Default
`pg_num`	Yes
`target`	No
`pool_name`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 12, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=true, idempotentHint=false), but the description adds genuinely new context: a [WRITE][risk=medium] tag and, importantly, that the change is reversible to the prior pg_num (matched by the undo_list/undo_apply siblings). This is useful beyond what annotations provide.

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?

Front-loads the mutation/risk tags and one-line purpose before a scannable Args block. Every line carries information with no filler.

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 destructive, non-idempotent 3-param mutate tool with no output schema, the description covers purpose, risk, reversibility, and every parameter. It could go further on consequences (data rebalancing load, health-state preconditions), but is largely complete.

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

Parameters4/5

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

Schema coverage is 0%, so the description carries the full burden, and it documents all three parameters: pool_name (with its source tool), pg_num (new placement-group count), and target (Ceph target name, omit for default). It only omits validation detail such as pg_num power-of-two expectations.

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 precise verb and resource ('Set a pool's pg_num'), naming the exact configuration field being mutated. This clearly separates it from sibling setters such as set_pool_size, set_pool_quota, and set_pool_autoscale.

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 only implied: 'pool_name (from pool_ls)' hints that pool_ls must be called first to discover a valid name, and target notes 'omit for the default'. There is no explicit statement of when to prefer this over set_pool_autoscale or any prerequisite about cluster health before rebalancing.

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