design_add_river

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the perspective flow behavior and configurable visual traits, and 'Add ... layer' implies a creation operation. It omits side effects, whether existing layers are affected, layer ordering behavior, and any return or rendering details.

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 and compact, explaining what is created before listing options. The long preset enumeration duplicates the schema enum, and the phantom 'ripple intensity' reference adds noise, but the overall structure is efficient.

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?

Given 11 optional parameters, no annotations, no output schema, and many overlapping landscape/water siblings, the description covers the visual concept and preset choices adequately. It does not explain creation side effects, relevant sibling alternatives, or how this layer integrates with tools like design_add_shore or design_add_reflection.

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 the schema already documents all 11 parameters, including enums and defaults. The description adds some mapping by naming path shape and bank style, but it also references 'ripple intensity,' which has no corresponding schema parameter, creating minor confusion rather than meaningful added semantics.

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 states a specific verb and resource: 'Add a perspective river/stream layer.' It also clarifies the visual orientation, with the river flowing from background to foreground. It does not explicitly distinguish this tool from nearby siblings like design_add_water_surface or design_create_river_scene.

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 description implies usage by naming the layer type and telling the user to choose a preset or customize path shape, bank style, and ripple intensity. However, it gives no explicit when-to-use guidance against alternatives, no exclusions, and no routing among the many water and landscape sibling tools.

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