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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds genuine value beyond them by explaining what is (and is not) destroyed: the code is invalidated while already-registered members remain members.

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 core effect and the when-to-use guidance are front-loaded and compact. The trailing '| EN: invitation, invite, voucher, code, bundle' is keyword padding that adds no operational meaning, slightly diluting the otherwise tight text.

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 single-param mutation with full annotation coverage and no output schema, the description covers effect, scope and code discovery adequately. Only minor gaps (e.g., behavior when the code is already inactive) remain, and idempotentHint largely covers those.

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 coverage is 100% and the code_id property already documents the status=inactive effect. The description adds acquisition guidance ('Den Code findest du mit list_invite_codes') not present in the schema, which helps the agent source the ID.

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?

States a specific verb (ungueltig machen / revoke) and resource (Einladungscode), plus the precise effect: no new registrations, existing members unaffected. This cleanly separates it from sibling tools like create_invite_code, redeem_invite_code and list_invite_codes.

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?

Explicitly names the triggering conditions (expired or misused codes) and points to list_invite_codes as the way to obtain the code. It does not spell out exclusions against siblings such as redeem_invite_code, but the intended usage is unambiguous.

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