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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered; the description adds genuinely useful blast-radius detail beyond them: existing members survive and only the code is invalidated. It does not mention permission requirements or whether the revoke is reversible, so it is not a full 5.

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 content is front-loaded and tight: what it does, what it preserves, and when to use it. The trailing '| EN: ...' keyword block is search metadata rather than agent-facing guidance and slightly dilutes the prose.

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-parameter mutation with full annotation coverage and no output schema, the description covers effect, scope, use case, and identifier sourcing. Nothing an agent needs to invoke it correctly is missing.

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 schema description already explains that it sets status=inactive while existing members remain. The description contributes only the note about where to find the code (list_invite_codes), so baseline 3 is appropriate.

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 states a specific verb and resource ('Einen Einladungscode ungueltig machen') and immediately scopes the effect ('keine neuen Registrierungen mehr darueber'). It is clearly distinguishable from the adjacent create_invite_code / redeem_invite_code siblings, and it explicitly names list_invite_codes as the companion lookup tool.

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?

It gives explicit when-to-use guidance ('Nutze es bei abgelaufenen oder missbraeuchten Codes') and tells the agent how to obtain the required identifier via list_invite_codes. No when-not condition or contrasting action is stated, so it falls short of a 5.

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