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

Far exceeds the annotations (destructiveHint/openWorldHint). Discloses that alias mail is typically rejected, that a catch-all may swallow it instead, that the mailbox and its messages are unaffected, that both mailbox and alias are validated server-side, and that the hosting system reports false success for non-existent aliases — with an explicit instruction never to report that case as done.

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 operation and its inverse are front-loaded in the first clause, and every sentence carries operational weight (the false-success warning is essential). It is nonetheless long and slightly repetitive — the closing 'Neu einrichten lässt sich ein Alias jederzeit mit set_email_alias' restates the opening and could be cut.

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?

Complete for a destructive mutation with no output schema. Consequence disclosure, prerequisite lookup, validation behavior, and the critical false-success edge case are all covered, leaving an agent nothing substantive it could get wrong.

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%, so the schema already documents all three required parameters including accepted local-part vs. full-address formats. The description reinforces sourcing values from get_email_accounts and that the alias must belong to exactly this mailbox, but adds no new format or syntax beyond the schema — baseline 3.

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 precise verb and resource ('Entfernt EINE Alias-Adresse von einem Postfach') and explicitly names set_email_alias as the inverse operation, so an agent can distinguish it from the sibling without opening either schema.

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?

Provides explicit when-to-use context (must verify via get_email_accounts first, 'rate keinen'), names the alternative for re-creation, and specifies a pre-removal condition (ask the customer whether the address is still published). Nothing is left to inference.

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