list_collections

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

Annotations already cover safety (readOnlyHint, idempotentHint) and scope (openWorldHint), so the description only needs to add workflow context. It does: the result is a lightweight id + one-sentence-description listing, and those ids are the canonical input for sibling tools — useful planning information not present in annotations. It omits any mention of network/catalog-specific caveats or result size.

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, purpose first, chaining guidance second — every clause earns its place with no repetition of schema or annotation content.

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 one-parameter, optional-argument, output-schema-backed read tool with annotations, the description supplies purpose and the downstream workflow, which is the main thing an agent needs. The only gap is that it doesn't hint at catalog selection behavior, which the schema covers adequately.

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 100% and the single `catalog` parameter is fully documented with an enum and a default-behavior note. The description never mentions the catalog parameter, so it adds nothing beyond the schema; baseline 3 applies.

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 and resource ('List the collections available in a STAC catalog') plus what each entry contains ('a one-sentence description'). The second sentence ties the output ids to specific sibling tools, so an agent can immediately distinguish this discovery tool from search_scenes and get_scene_details.

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?

Explicitly tells the agent what to do with the result ('Use the returned ids as `collection` in search_scenes and get_scene_details'), which effectively establishes this as the discovery step before searching or fetching details. It stops short of any exclusion, e.g. when to skip listing and search directly, or how to choose between the two catalogs.

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