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 mentions 'Create or update' which implies mutation, but doesn't specify whether this requires admin privileges, if it's idempotent, what happens on conflicts, or what the response looks like (e.g., success confirmation or error). For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 directly states the tool's purpose without unnecessary words. It's appropriately sized and front-loaded with the core action, making it easy to parse quickly.

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 mutation tool with 6 parameters, no annotations, and no output schema, the description is insufficient. It doesn't cover behavioral aspects like permissions needed, idempotency, error conditions, or response format. While the schema covers parameter documentation well, the description fails to provide the necessary context for safe and effective 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?

Schema description coverage is 83% (5 out of 6 parameters have descriptions), so the schema already documents most parameters well. The description adds minimal value by mentioning 'cluster and index privileges' which corresponds to two parameters, but doesn't explain the other four parameters or provide additional context beyond what's in the schema. This meets the baseline for high schema coverage.

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 action ('Create or update') and resource ('a role') with specific privilege types ('cluster and index privileges'), which provides a specific verb+resource combination. However, it doesn't explicitly distinguish this tool from sibling tools like 'create_user' or 'get_role', which would require mentioning it's for role management specifically within a security/privilege context.

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. It doesn't mention prerequisites (e.g., authentication, permissions), when to choose 'create' vs 'update', or how it differs from related tools like 'create_user' or 'delete_role'. Without this context, an agent might struggle to select this tool appropriately.

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