Elasticsearch/OpenSearch MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states 'Create a new index' which implies a write/mutation operation, but it doesn't specify permissions required, whether this is idempotent, potential side effects, error conditions, or what happens on success. For a creation tool with zero annotation coverage, this is a significant gap in transparency.

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 appropriately sized with a clear purpose statement followed by parameter explanations in a structured format. Every sentence adds value, and there's no redundant information. It could be slightly more front-loaded with key behavioral details, but overall it's efficient and well-organized.

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 complexity of a creation tool with no annotations, no output schema, and 2 parameters (one optional with nested configuration possibilities), the description is incomplete. It lacks information on what the tool returns, error handling, dependencies, or how it fits into broader workflows with sibling tools like 'index_document'. This makes it inadequate for reliable agent use.

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 description adds basic semantics for both parameters ('index: Name of the index' and 'body: Optional index configuration including mappings and settings'), which provides meaning beyond the 0% schema description coverage. However, it doesn't detail format constraints, examples, or how 'body' interacts with 'index', leaving some ambiguity. With 2 parameters and low schema coverage, this is adequate but not comprehensive.

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 states 'Create a new index' which clearly indicates the verb and resource, but it's somewhat vague about what an 'index' represents in this context. It doesn't distinguish this tool from similar operations like 'index_document' or 'get_index' among the sibling tools, leaving room for confusion about the specific domain.

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 provides no guidance on when to use this tool versus alternatives. With sibling tools like 'index_document' and 'get_index' available, there's no indication of prerequisites, typical use cases, or distinctions between creating an index and other index-related operations, leaving the agent to infer usage context.

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