design_create_ecosystem

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

No annotations exist, so the description carries the full burden. It usefully discloses render order (back-to-front), depth-based scaling and color shifting, which are real behavioural traits an agent could not read off the schema. It says nothing about determinism/seeding, what object is returned, or whether the scene is created in a new sketch or the current one — gaps that matter for a creation tool.

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?

Three tight sentences: what it makes, how it renders, how to lay it out. The core capability is front-loaded and every sentence contributes new information with no 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?

For a 7-parameter creation tool with full schema coverage and no output schema, the description covers the essential mental model — layered plants with depth, fog/perspective and ground, plus the two layout modes. What is missing is the placement in the broader workflow (does it create a new sketch? how does it relate to design_create_garden?), which keeps it from a 5.

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 the schema already explains fog, ground, depth lanes, scale and enum values. The description restates the arrangement presets and the auto-vs-explicit position choice but adds no syntax, units, or interaction semantics (e.g. how depth interacts with arrangement) beyond the schema. Baseline 3 is appropriate.

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 gives a specific verb and resource — creating an ecosystem scene composed of multiple plants — and adds distinguishing scope (depth arrangement, atmospheric perspective, optional ground plane). It does not explicitly name the neighbouring tools it differs from (design_create_garden, design_add_plant, design_create_landscape), so an agent must infer the boundary.

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?

The third sentence tells the agent how to choose between two modes: use arrangement presets for auto-layout or give explicit x/y positions. That is genuine guidance, but only about parameters. There is no statement of when to reach for this tool instead of design_create_garden or design_add_plant, which sit right beside it in the toolset.

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