Retrieve a list of all indices in an Elasticsearch cluster, optionally filtered by a pattern.
List all indices in the cluster
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "es_list_indices"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| pattern | No | Index pattern (default: '*') |
Changes observed during successful MCP inspections.
v1.0.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It only states 'list' without indicating whether the operation is read-only, safe, or has any side effects. No mention of permissions, rate limits, or output details.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence with no unnecessary words. It is front-loaded and efficient, conveying the core purpose directly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
While the tool is simple (one optional param, no output schema), the description lacks information about the return format, pagination, or any limitations. For a tool targeting cluster indices, a brief note on output or performance would improve completeness.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% and the description adds no value beyond the schema. The parameter 'pattern' is documented in the schema with its default, but the description does not reference it or clarify its usage.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'List all indices in the cluster' clearly states the verb (List) and resource (indices), and implies the scope. It distinguishes from siblings like es_create_index or es_search, but does not explicitly differentiate from other list-like tools.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives such as es_cluster_info or es_search. There is no mention of prerequisites, when not to use it, or typical use cases.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.