get_capabilities

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

With no annotations, the description carries the burden of explaining behavior. It discloses that the tool maps conformance classes to human-readable names and provides examples (query, sort, fields, aggregations), but it does not mention any side effects, permissions, or output structure details. This is adequate but not rich, so a score of 3 is appropriate.

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 two sentences, front-loaded with the primary action, and every sentence adds value. The second sentence enriches the first with concrete examples, containing no wasted words.

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?

The tool has only two optional parameters, an output schema, and a relatively simple purpose. The description provides sufficient overview and context (mapping behavior and examples) to understand when and why to use it. The presence of an output schema lessens the need to describe return values, so a score of 4 is justified.

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?

Input schema coverage is 100%, with clear descriptions for both parameters (catalog_url and output_format). The tool description does not add any additional meaning to these parameters; it only describes the overall capability mapping. Since the schema already fully documents the parameters, the baseline of 3 is warranted.

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 clearly states the tool's purpose: 'Return a summary of STAC API capabilities.' It also adds specificity by explaining the mapping from conformance classes to human-readable capability names, which distinguishes it from the sibling get_conformance tool.

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 phrase 'making it easier for agents to discover what features a catalog supports' gives clear usage context. It does not explicitly name alternatives, but the contrast with raw conformance listing is implied, which is sufficient for a guidance score of 4.

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