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

No annotations are provided, so the description carries the full burden. It discloses auth requirements (AGENT KEYS ONLY, refused before charge), cost (150 J metered, all-in 151), refund policy (full refund if no image delivered), failure semantics (available:false is a result, not an error; never fabricated), and output structure. This is comprehensive behavioral disclosure.

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 dense but front-loads the core purpose and key parameters well. However, the later sections (RETURNS, unavailable semantics) are somewhat verbose and could be tightened. It includes useful edge-case details but at the cost of length, bordering on over-specification for a tool call description.

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 6-parameter tool with no annotations, no output schema, and 0% schema description coverage, the description is remarkably complete. It covers purpose, parameters, auth, cost, refunds, return format, provenance fields, and failure modes — everything an agent needs to invoke and interpret 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 0%, so the description must compensate. It explains pose via lat/lng OR entity_type+id, as_of format (YYYY-MM-DD, newest scene on/before date), max_cloud range (0-100, default 20), and even clarifies that entity_cap_consumed is 0. This fully compensates for the missing schema descriptions.

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 verb (satellite still image) and resource (Sentinel-2 archive scene), and explicitly differentiates from the sibling `look_from` by naming it ('same pose family as `look_from`'). Clearly tells the agent this returns an image rather than coordinates or metadata.

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?

Defines when an image is unavailable (cloudy or missing scene returns available:false, refunded) and distinguishes archive from live. However, it does not explicitly state when to choose this over `look_from` — it only notes they share a pose family, leaving the agent to infer the difference (still image vs whatever look_from provides).

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