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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior, so the bar is lower. The description adds useful context beyond annotations: the upstream refuses catalogue-wide search, collections is mandatory, and bbox uses WGS84 [west, south, east, north]. It also discloses the kind of data returned, though it does not cover rate limits or auth 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?

Three tightly packed sentences with no filler: the first states purpose and return fields, the second establishes authoritative usage, and the third covers the required parameter and bbox format. The critical constraint, collections is REQUIRED, is front-loaded appropriately.

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 rich annotations and 100% schema coverage, the description completes the picture by explaining authoritative live-index behavior, the mandatory collections parameter, and the bbox coordinate order. It also summarizes the returned payload even though no output schema exists. An agent has enough to call the tool correctly.

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 description coverage is 100%, so the schema already documents every parameter thoroughly. The description repeats the required-collections rule and bbox ordering but adds little semantic detail beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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: search Planetary Computer satellite imagery and environmental data by area and date. It also lists the return fields, making the operation clear. It does not explicitly differentiate itself from sibling collection/catalogue tools, so 4 rather than 5.

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?

It gives a clear use context: AUTHORITATIVE for discovering what imagery exists over a place and date range, querying the live index rather than a description. It also notes that collections is required and catalogue-wide search is refused. It does not name a specific alternative sibling tool for other catalogue needs.

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