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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful account scoping by saying 'gemerkte Objekte des angemeldeten Kontos' and repeats that it is read-only, but it does not describe return format or pagination behavior.

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 definition is front-loaded with the core purpose and then routes the agent to alternatives efficiently. The trailing English keyword line ('EN: favorite, bookmark, quick access') is slightly extraneous for invocation, but the overall structure is compact and useful.

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 zero-parameter list tool with rich annotations and no output schema, the description provides enough context: it identifies the resource, the account scope, the read-only nature, and the relevant sibling alternatives. Nothing critical is missing for correct invocation.

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?

This tool has zero parameters, so there are no parameter semantics to explain. The baseline for a zero-parameter tool is 4, and the description appropriately does not invent parameter details.

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 uses a specific verb and resource: 'Die eigenen Favoriten auflisten' and clarifies that these are saved objects of the logged-in account. It also distinguishes the tool from sibling operations by naming onto_favorite_add, onto_favorite_delete, and onto_object_index.

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 explicitly states the use case: quickly accessing frequently used objects. It also gives concrete alternatives for adding, removing, and listing all objects, leaving little ambiguity about when to choose this tool versus its siblings.

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