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

Annotations only cover the safety profile (readOnly/destructive), so the description adds substantial new behavior: live read from the hosting system, server-side domain validation against this customer's contracts, handling of a duplicated/contradictory upstream response, and the critical distinction between an empty list and a field that was never read. These are non-obvious traits an agent cannot derive from structured fields.

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?

Front-loaded with purpose and the set/verify relationship, and the two downstream caveats are clearly numbered. It is longer than typical and the parenthetical asides add bulk, but every sentence carries operational content rather than filler.

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?

There is no output schema, so the description must describe returns — and it does: state, protected extensions, permitted foreign domains, plus explicit guidance on how to report contradictory or unread values. Given the single required parameter and absent output schema, an agent has everything needed to call and interpret this correctly.

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 schema itself is thin (just an example format), so the baseline would be 3. The description adds real semantics beyond it: the domain must belong to this customer and a foreign domain is rejected before anything is read. It does not, however, discuss case handling, subdomain vs apex matching, or validation-error behavior.

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+resource ('Liest den Hotlink-Schutz EINER Domain') and enumerates exactly what is read: on/off state, protected file extensions, and allowed foreign domains. It explicitly positions itself against the sibling set_hotlink_protection as its read counterpart.

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?

Gives explicit when-to-use ('Vor jedem Setzen sinnvoll') with the concrete reason that a set list REPLACES the existing one, and names the alternative read route ('der einzige Weg, eine Änderung daran nachzuprüfen'). Nothing about selection 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.