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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description adds real behavioral context beyond that: a 409 conflict on an occupied character view, that it does NOT steer generation, that beschreibung_ableiten won't overwrite an existing description unless ersetzen is set, the downstream likeness check on every later generation, and the cost profile (free except one vision call).

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-loads the core action ('Attach an existing project image ... as reference') before branching into the two ziel modes, and every clause carries operational content. It is a dense, near run-on single paragraph, which costs a point on readability but not on waste.

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 an 8-parameter, conditional, no-output-schema tool, the description covers mode branching, defaults, required-ness, conflict handling, side effects and cost. It does not say what the call returns (e.g. the updated reference record), a minor gap given no output schema exists.

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?

With schema coverage at 63%, the description compensates well: it documents the default view of 'detail' (the face anchor) and the purpose of view values, clarifies that personenbezug has no default and is required for characters, and ties ersetzen to both the 409 bypass and the description overwrite. It adds meaning the schema descriptions alone don't carry.

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 (attach) and resource (an existing project image as reference) and immediately scopes the two targets, figur vs location. An agent can distinguish it from lab_generate (which creates images) and from lab_generate_character_reference 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?

Explains when each ziel branch applies, names the exact upstream tools that produce a valid image_id (lab_umzug, lab_get_job result.bildzeilen, lab_generate), and states preconditions (personenbezug mandatory for characters, likeness_ref for reale_person). It stops short of explicitly routing away from neighbouring generation tools, so 4 rather than 5.

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