Order area download (email)

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

Adds meaningful behavior beyond the annotations: the operation spends API credits, requires prior cost estimation plus user consent, is capped at 3,000 km², and results arrive asynchronously by email. Annotations (readOnly=false, idempotent=false, destructive=false) only tell the agent it is a non-repeatable write; the credit cost and email delivery are the valuable additions.

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?

Two short sentences, both front-loaded: what the tool produces first, then the cost warning. Every clause carries decision-relevant 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?

Covers the essentials for a 5-parameter, no-output-schema tool: what is produced, the area constraint, the cost prerequisite, and how the result reaches the user (email). It leaves minor gaps such as what the immediate response contains (confirmation or job reference) and expected turnaround.

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 80%, so bbox, area_wkt, start/end and variables are already documented in the schema. The description only contributes the 3,000 km² area limit tied to bbox/area_wkt and adds no guidance on which geometry parameter to use or how variables are chosen.

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?

States a specific resource (daily GeoTIFF rasters clipped to an area), the size cap (max 3,000 km²), and the delivery mechanism (server-prepared, emailed). This clearly separates it from immediate-download siblings like download_gridded_files and from point-based request_point_history, though no sibling is named explicitly.

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?

Gives an explicit prerequisite workflow: run estimate_area_download first and obtain the user's agreement to the cost. That is concrete routing to a named alternative, but it does not say when to prefer this over request_point_history or how to choose between bbox and area_wkt.

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