fill_sinks

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

Without annotations, the description must disclose behavioral traits. It states the operation (fill sinks), license requirement, and optional z_limit parameter. However, it does not clarify that the input raster is not modified, that a new output raster is created, or discuss overwrite behavior. The description provides basic context but lacks depth.

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 concise with three sentences, each serving a distinct purpose: action, use case, and additional requirements. It is front-loaded and contains no superfluous information.

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 raster analysis tool with an output schema and a single composite parameter, the description covers the essential use case, license, and key parameter. It is adequate for an agent to understand the tool's purpose and when to invoke it, though it could mention output characteristics.

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?

The input schema already provides detailed descriptions for all parameters (in_raster, out_raster, z_limit, overwrite). The description adds context for z_limit (controls maximum sink depth) but does not significantly augment the schema's explanations. With high schema coverage, the description's added value is marginal.

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 clearly states the tool fills sinks/depressions in elevation rasters using ArcPy Spatial Analyst Fill. It specifies the context of hydrologically conditioning DEMs before flow direction, accumulation, watershed, or stream network analysis, which distinguishes it from sibling raster tools.

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 provides explicit guidelines on when to use the tool: for hydrologically conditioning DEMs before hydrologic analyses. It also mentions the required Spatial Analyst license. It does not explicitly state when not to use it, but the context is clear.

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