Elastic 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 mentions filtering capabilities but doesn't describe key behaviors such as whether this is a read-only operation (implied by 'List'), what permissions are required, if there are rate limits, pagination handling, or the format of returned data. For a tool with no annotation coverage, this leaves significant gaps in understanding how it behaves beyond basic functionality.

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 extremely concise—a single sentence that efficiently states the action and filtering options without any wasted words. It's front-loaded with the core purpose ('List API keys') and follows with essential details. Every part of the sentence earns its place by contributing directly to understanding the tool's functionality.

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 (a list operation with filtering), lack of annotations, and no output schema, the description is incomplete. It doesn't address behavioral aspects like safety, permissions, or response format, which are critical for an AI agent to use this tool correctly. While the purpose is clear, the description fails to compensate for the missing structured data, leaving gaps in contextual understanding.

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 100%, with all three parameters ('owner', 'name', 'realm_name') fully documented in the input schema. The description adds minimal value by listing the filterable fields ('owner, name, or realm'), which aligns with but doesn't expand upon the schema. Since the schema does the heavy lifting, the baseline score of 3 is appropriate, as the description doesn't provide additional syntax, examples, or constraints beyond what's in the structured data.

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 verb ('List') and resource ('API keys'), making the purpose immediately understandable. It distinguishes from siblings like 'create_api_key' and 'invalidate_api_key' by focusing on retrieval rather than creation or modification. However, it doesn't explicitly differentiate from other list tools like 'list_indices' or 'list_users' beyond the resource type.

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 through the mention of filtering capabilities ('Can filter by owner, name, or realm'), suggesting this tool is for retrieving API keys with optional filtering. However, it doesn't provide explicit guidance on when to use this versus alternatives like 'get_user' (which might include API key info) or when filtering is necessary versus retrieving all keys. No exclusions or prerequisites are mentioned.

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