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 carried structurally; the description adds the substantive constraint that only drafts are deletable and issued documents are not. It doesn't mention permissions or behavior when the id doesn't exist, so not a 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?

Two short sentences: the action first, then the exclusion and alternatives. Every clause earns its place, with no repetition of the title or schema.

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 purpose, scope, and correct alternatives. A note on not-found/idempotent behavior would make it fully complete.

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?

Only one parameter with 100% schema description coverage ("Beleg-ID"), so the schema fully documents it. The description adds nothing about id format or lookup failure, which is acceptable at this coverage level but no better than baseline.

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 Entwurf löschen") and immediately scopes it against issued documents, which cannot be deleted. This lets an agent distinguish delete_draft from siblings like cancel_invoice without opening any 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?

Explicitly names the when-not condition ("Ausgestellte Belege lassen sich nicht löschen") and routes to the two correct alternatives, cancel_invoice and create_credit_note. No inference required.

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