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

Goes well beyond the annotations: it discloses that membership is permanent while the code expires, that rights are only upgraded never downgraded, that all scope managers are notified, that all failure modes return an identical 400, and that 10 failures/hour per account+IP trigger a 429 that must not be retried. That is exactly the operational context an agent needs before a non-idempotent write.

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 purpose and the 'use when' condition are front-loaded, and the error/rate-limit sentences earn their place for a write tool. It is dense but not padded; the trailing keyword aliases aid retrieval rather than adding noise.

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?

With only two fully documented parameters, no output schema, and existing annotations, the description fills the remaining gaps: side effects, error semantics, rate limiting, and the accept_management escalation path. An agent has everything needed to invoke it correctly and recover from failure.

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 both parameters already carry detailed descriptions, including the accept_management warning behavior. The description adds little parameter-specific meaning beyond what the schema provides, so the baseline of 3 applies.

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 and resource ('Einen Einladungscode einloesen') and immediately clarifies the effect: it writes membership and is the self-registration path that needs no administrator. This distinguishes it cleanly from create_invite_code, list_invite_codes and revoke_invite_code in the sibling set.

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 says 'Nutze es, wenn du einen Code erhalten hast' and names list_invite_codes as the issuer-side management alternative, plus a second usage path (entering a foreign scope with a code). It gives clear positive conditions but no explicit 'do not use this when...' exclusion.

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