copernicus_search

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

With no annotations, the description carries the full burden and does well: it discloses that search and preview-URL retrieval need no authentication, while downloading images requires a CDSE OAuth2 account. It also states the return payload shape (content summary, structuredContent JSON with id/datetime/bbox/cloud cover/preview URL). It doesn't mention rate limits or failure modes, but the auth and return-format disclosure is substantial.

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?

Well front-loaded: one-line purpose, auth caveat, return shape, then an Args block per parameter. Every section earns its place. The natural-language example lines are slightly redundant given the Args block, but they aid intent matching, so the size is justified.

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 5-parameter STAC search with no annotations, no output schema, and 0% schema coverage, the description supplies everything needed: purpose, auth behavior, return payload contents, and per-parameter formats with examples. Nothing critical is missing for correct invocation.

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% and there are 5 parameters, so the description must compensate fully — and it does. Every parameter gets meaning: collection ID with default and cross-reference to copernicus_collections, bbox format 'lon_min,lat_min,lon_max,lat_max' with a Tokyo example, datetime format 'YYYY-MM-DD' or 'start/end' with a concrete range, max_cloud_cover in percent and its applicability condition, and limit default 5 / max 10.

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 (search/検索) and resource (ESA Copernicus satellite imagery via STAC) and gives concrete examples (東京のSentinel-2画像). The sibling copernicus_collections is explicitly named as the way to discover collection IDs, distinguishing the two 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?

Clearly explains when this tool applies (searching Sentinel imagery), notes that search requires no auth, and points to the sibling copernicus_collections for valid IDs. Also gives examples of natural-language intents it serves. It does not, however, contrast with stac_search or uk_stac_search, so the agent must infer which STAC endpoint to choose.

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