stac_zonal_stats

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

No annotations provided, so description carries full burden. It discloses return of per-zone statistics and optional z-score anomaly detection, explains the logic, and notes the raster must be a GeoTIFF. Side effects and auth are not mentioned, but the read-only nature is implied.

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 well-structured with a summary, zone explanation, anomaly section, and parameter list. It is front-loaded with purpose. While long, every sentence adds value. Minor redundancy in zone explanation but overall 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?

With 10 parameters, no output schema, and no annotations, the description covers all parameters, return values, and usage context. It mentions projection requirements and anomaly detection logic. Lack of explicit return format is compensated by clear per-zone statistics mention.

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 0%, so description compensates fully. Each parameter is explained: points format, buffer_m meaning, geojson types, zones_crs examples, background_m enabling anomaly detection, etc. This adds substantial meaning beyond the schema types.

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 reads raster values within zones, specifying it as the inference step after fetch. It distinguishes between buffer and polygon zones and gives concrete examples (NDVI index, GeoTIFF). This is specific and differentiates from sibling 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 clear context on when to use (after fetch, with stored raster artifacts) and explains two zone input modes. It implicitly excludes PNG previews and gives anomaly detection use case. While it doesn't explicitly name alternatives, the context makes usage clear.

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