Elastic MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool retrieves statistics (implying a read-only operation) but doesn't clarify permissions required, rate limits, response format, or whether it's a real-time or cached view. This leaves significant gaps for a tool that likely interacts with a critical system like Elasticsearch.

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, efficient sentence that front-loads the core purpose ('Get comprehensive cluster statistics') and adds useful scope details. Every word earns its place, with no redundancy or fluff.

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?

Given the tool's complexity (cluster-wide statistics in what appears to be an Elasticsearch context) and lack of annotations or output schema, the description is minimally adequate. It specifies what statistics are included but doesn't address behavioral aspects like permissions or response format, which are important for such a system-level tool.

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?

The tool has zero parameters, and schema description coverage is 100% (since there are no parameters to describe). The description adds no parameter information, which is appropriate here. Baseline for zero parameters is 4, as there's nothing for the description to compensate for.

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 clearly states the tool's purpose with a specific verb ('Get') and resource ('comprehensive cluster statistics'), including the scope ('indices, nodes, and resource usage'). It distinguishes itself from siblings like 'cluster_health' or 'nodes_stats' by emphasizing comprehensiveness, though it doesn't explicitly name alternatives.

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?

The description implies usage for obtaining broad cluster metrics, but provides no explicit guidance on when to use this tool versus alternatives like 'cluster_health' or 'nodes_stats'. It lacks any 'when-not' scenarios or prerequisites, leaving the agent to infer context from the tool's name and description alone.

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