zonal_statistics

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

With no annotations, the description bears full burden. It mentions the requirement for a Spatial Analyst license, which is a key behavioral trait. However, it does not disclose side effects like file creation, permission needs, or error conditions. The description is adequate but not rich.

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 two sentences with no redundancy. It front-loads the core action and then adds usage guidance and a dependency. Every sentence earns its place.

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 the presence of an output schema and detailed parameter descriptions, the description is mostly complete. It misses clarifying that the output raster is created at the specified path and that overwrite needs true for existing outputs, but these are clear from the schema. The description covers the main purpose and key constraint (license).

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 provides detailed descriptions for all parameters, so the schema_description_coverage is effectively high. The description mentions 'MEAN, SUM, MIN, MAX, or similar value', which aligns with the statistics_type parameter but adds no new information. The description does not compensate for any missing schema details.

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 it calculates one raster statistic per zone and writes the result as a raster. It specifies the verb 'calculate' and the resource 'one raster statistic per zone'. It implicitly differentiates from the sibling 'zonal_statistics_as_table' by emphasizing raster output, but does not explicitly name the alternative.

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 clear guidance: 'Use this when each zone should receive a MEAN, SUM, MIN, MAX, or similar value'. It does not explicitly say when not to use or list alternatives, but the context is sufficient for typical usage.

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