Zitadel MCP

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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds valuable context by specifying that it 'Shows key metadata only (not private keys)', which clarifies output limitations beyond what annotations provide. No contradictions with annotations exist.

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 two concise sentences with zero wasted words, front-loading the core purpose and efficiently adding a key behavioral detail. It's appropriately sized for a simple tool.

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 tool's low complexity (1 parameter, no output schema), rich annotations covering safety, and clear purpose, the description is largely complete. It could slightly improve by mentioning output format or pagination, but the metadata clarification compensates well for the lack of output schema.

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 input schema has 100% description coverage, with 'userId' clearly documented as 'The service account user ID'. The description doesn't add any parameter details beyond the schema, so it meets the baseline for high schema coverage without extra value.

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 ('List existing keys') and resource ('for a service account'), with the clarifying detail about showing only metadata. It distinguishes from sibling tools like 'zitadel_create_service_user_key' by focusing on listing rather than creation, though it doesn't explicitly differentiate from other list tools like 'zitadel_list_apps'.

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 when needing to view keys for a specific service account, but provides no explicit guidance on when to use this versus alternatives, prerequisites, or exclusions. It doesn't mention when not to use it or refer to other tools for related operations.

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