Zitadel MCP

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

Annotations indicate this is a non-readOnly, non-idempotent, non-destructive operation. The description adds valuable behavioral context: it explicitly warns that 'The private key is returned ONLY at creation time — save it immediately,' which is critical for security and operational awareness beyond what annotations provide. However, it doesn't mention rate limits, authentication requirements, or error conditions.

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, well-structured sentence that efficiently conveys the core action and critical warning. Every word earns its place—no fluff or redundancy, and the key behavioral detail is front-loaded.

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 write operation with security implications), lack of output schema, and rich annotations, the description is partially complete. It covers the main action and a crucial behavioral warning but omits details like response format, error handling, or prerequisites. It's adequate but has clear gaps for a tool that generates sensitive credentials.

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 clear parameter documentation in the schema itself. The description doesn't add any parameter-specific details beyond what's in the schema (e.g., it doesn't explain key formats or default behaviors for expirationDate). Baseline score of 3 is appropriate since the schema carries the full burden.

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 specific action ('Generate a new key pair') and target resource ('for a service account'), distinguishing it from sibling tools like 'zitadel_create_service_user' (creates the account itself) or 'zitadel_list_service_user_keys' (lists existing keys). It goes beyond just restating the name/title.

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., needing an existing service account), compare to sibling tools like 'zitadel_list_service_user_keys', or specify scenarios where key generation is appropriate versus other operations.

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