list_eo_catalogs

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 explains that the registry is data-driven via config/catalogs.yaml, names the current catalog and contents, and specifies the returned dictionary structure. For a read-only, no-argument list operation, this is strong transparency.

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 first sentence states the purpose immediately, and the 'Usage' and 'Returns' sections provide practical, scannable guidance. The listing of catalog contents is slightly redundant with the Returns section but not excessive.

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?

This is a simple zero-argument tool, and the description covers its trigger, output, and relationship to following search steps. There are no missing details that would prevent an agent from selecting or invoking it 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?

The tool has zero parameters, so the description has no parameter semantics to add. The baseline for zero-parameter tools is 4, and the description appropriately focuses on what the output represents instead.

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 opens with a specific verb and resource: 'Lists the Earth observation STAC catalogs registered on this server.' It also distinguishes itself from sibling search tools by stating this is the discovery step before using search_eo_datasets / search_eo_scenes.

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?

The description explicitly says 'Call once to see where EO data can be discovered from before using search_eo_datasets / search_eo_scenes.' This gives clear sequencing and routing, making it obvious when this tool should be selected over its siblings.

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