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

Annotations already declare readOnly=false, destructive=false, and non-idempotent. The description adds the critical side effect that this changes the schema and that existing objects will have the field empty afterward, which is exactly the kind of behavioral context an agent needs beyond the annotations.

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 description is front-loaded with the main action and side effect, then immediately routes away from the sibling tool. The trailing English keyword list is compact but slightly redundant, keeping it just below maximally concise.

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 10-parameter mutation tool with full schema coverage and no output schema, the description covers purpose, usage, schema-modification impact, and the main alternative. It does not describe the return value or duplicate-key/error behavior, but the essential invocation context is present.

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 description coverage is 100%, so all 10 parameters, including scope_id permission implications and value_type options, are already documented in the input schema. The description adds context about the field being part of the object model but does not add parameter-level meaning beyond the schema, so the baseline 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?

The description names a specific verb and resource: creating a new property definition / field in the object model. It explicitly distinguishes this from setting values on an object by naming onto_object_set_property as the wrong tool for that job.

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 states when to use it ('beim Modellaufbau') and gives an explicit when-not with the correct alternative: use onto_object_set_property for setting values, not this tool. This leaves little ambiguity for tool selection.

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