Elasticsearch/OpenSearch MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions the tool performs HTTP requests but doesn't describe authentication requirements, rate limits, error handling, response formats, or what types of operations are possible. For a general-purpose API tool with 4 parameters, this leaves significant behavioral aspects undocumented.

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 efficiently structured with purpose first, usage guidelines second, and parameter explanations in a clear Args section. Every sentence adds value without redundancy, and the formatting makes it easy to parse despite the multi-line presentation.

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?

For a general-purpose API tool with 4 parameters, no annotations, and no output schema, the description provides adequate basics but lacks important context. It covers purpose and usage well but misses behavioral details like authentication, error handling, and response structure. The parameter explanations are minimal but exist, making this complete enough for basic understanding but insufficient for confident 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 lists all 4 parameters with brief explanations, but with 0% schema description coverage, it doesn't fully compensate. It provides basic semantics (method is HTTP method, path is endpoint, params are query parameters, body is request body) but lacks format details, examples, or constraints. This is the minimum viable explanation given the schema's lack of descriptions.

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: 'Perform a general HTTP API request' and specifies it's for Elasticsearch/OpenSearch APIs without dedicated tools. It distinguishes from siblings by indicating this is a catch-all for APIs not covered by specific tools like create_index or search_documents. However, it doesn't explicitly name the resource being accessed beyond 'API'.

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 explicit usage guidance: 'Use this tool for any Elasticsearch/OpenSearch API that does not have a dedicated tool.' This clearly indicates when to use this tool versus the many specific sibling tools listed, establishing clear boundaries and alternatives.

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