AWS OpenSearch MCP Server

diagnose_cluster

Identify cluster health issues, shard problems, disk usage, and flood-stage blocks through an evidence-based read-only diagnosis.

Instructions

Generate an evidence-based read-only diagnosis for health, shards, disk and flood-stage blocks.

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": {
      "profile": "<profile>",
      "region": "<region>",
      "domain": "<domain>"
    },
    "name": "diagnose_cluster"
  }
}

Input Schema

Name	Required	Description	Default
`domain`	Yes
`region`	Yes
`profile`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 8, 2026

TDQS

B3.1/5.0

Behavior2/5

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

No annotations are provided, so the description carries full burden. It states 'read-only' indicating non-destructiveness, but lacks disclosure on permission requirements, performance impact, or potential failure modes. The scope is clear but behavioral traits are minimal.

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?

The description is a single sentence with no fluff, front-loading the key purpose and scope. Every word earns its place.

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

Completeness2/5

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

Given the complexity (3 required undocumented parameters) and existence of an output schema, the description fails to cover parameter semantics. While the tool may have good output documentation, the input side is critically incomplete.

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

Parameters1/5

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

Schema description coverage is 0%, yet the description does not explain any of the three required parameters (profile, region, domain). This is a major gap; the agent cannot infer what values to provide.

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?

The description clearly states the verb 'generate' and the resource 'read-only diagnosis' with specific scope: health, shards, disk, and flood-stage blocks. This distinguishes it from sibling tools like get_cluster_health or get_disk_allocation.

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?

The description implies usage as a comprehensive diagnostic tool via 'evidence-based read-only diagnosis,' but provides no explicit guidance on when to use it versus alternatives like get_cluster_health or explain_unassigned_shard. No when-not-to-use or prerequisites are mentioned.

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