list_registries

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions backward compatibility and performance considerations, which adds useful context. However, it lacks details on potential side effects, error handling, or output format (e.g., list structure, pagination). For a tool with no annotations, this leaves gaps in behavioral understanding.

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 highly concise and well-structured: two sentences that directly state the purpose and provide critical usage guidance. Every sentence adds value without redundancy, and it is front-loaded with the core functionality. No extraneous information is included.

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?

Given the tool's simplicity (0 parameters, no output schema, no annotations), the description is reasonably complete. It covers purpose and usage guidelines adequately. However, without annotations or output schema, it could benefit from more behavioral details (e.g., output format or error cases), slightly limiting completeness for a tool in a complex sibling set.

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 input schema has 0 parameters with 100% description coverage, meaning no parameters need documentation. The description does not discuss parameters, which is appropriate. A baseline of 4 is applied for zero parameters, as there is nothing to compensate for, and the description does not add unnecessary parameter information.

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: 'List all configured Schema Registry instances.' It specifies the verb ('List') and resource ('Schema Registry instances'), making it unambiguous. However, it does not explicitly differentiate from sibling tools like 'get_registry_info' or 'compare_registries', which might provide similar or overlapping functionality, preventing a perfect score.

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 provides explicit usage guidance: it notes that the tool is 'maintained for backward compatibility' and recommends using 'registry://names' resource instead for better performance. This clearly indicates when to use this tool (for backward compatibility) and when to prefer an alternative, covering both inclusion and exclusion criteria effectively.

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