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

Annotations only declare readOnlyHint=false and destructiveHint=false, so the description carries real weight and delivers: credit consumption, stufe cost/duration tradeoff (~1 min vs 5-15 min), asynchronous welt_id return, and the spatial limitation that the world only holds near the camera spot (reverse shots ok, flying through walls not).

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?

Dense but front-loaded and largely waste-free: purpose, cost, sources, async contract, follow-up workflow, limitation. Slight redundancy with the schema on stufe enum values and the get_cost wording keeps it off a 5.

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?

No output schema exists, yet the description still discloses the return value (welt_id) and the polling sibling, plus what happens after completion. For an async, credit-consuming generation tool with 7 parameters, nothing an agent needs to call it correctly is missing.

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%, so baseline is 3; the description still adds meaning by framing loc_id+variante as a coupled pair, describing quell_bild_id as the alternative source, and explaining what get_cost and each stufe actually do operationally.

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?

Names a specific verb and artifact: 'Build a walkable 3D WORLD (Gaussian splat, World Labs Marble) from ONE location picture.' The output type is unambiguous and clearly separates it from siblings like lab_location_recon, lab_location_panorama or lab_restyle_location.

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?

States the two admissible input sources (location board loc_id+variante versus a gallery image quell_bild_id), tells the agent to call with get_cost:true and name the price before a real run, and routes the async flow explicitly to lab_welt_status and onward to lab_generate via seed_image_url.

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