ncloud_list_cache_instances

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

The annotation readOnlyHint=true already covers the safety profile. The description adds the useful 'current region' scope constraint, but does not disclose pagination behavior, response format, or whether instances are returned regardless of status. With annotations reducing the burden, the description provides some but limited behavioral context, warranting a 3.

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 a single, concise sentence that front-loads the action and resource. It includes the clarifying parenthetical '(Redis/Valkey)' for precision, and contains no wasteful words. This is exemplary for a list operation.

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 simple list operation, the description covers the core purpose (list cache instances), the scope (current region), and the service (Cloud DB for Cache). The schema documents all parameters and the annotation indicates read-only safety. The main gap is the absence of an output schema or a note about pagination/default response, but this is not a significant deficiency given the tool's simplicity.

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 every parameter (pageNo, pageSize, cloudCacheServiceName, cloudCacheInstanceNoList) has a description. The tool description itself does not add any parameter-specific semantics, but the schema fully documents them. The baseline for high schema coverage is 3, and the description does not go beyond that.

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 uses an explicit verb and resource: 'List all Cloud DB for Cache (Redis/Valkey) instances' and adds a scope qualifier 'in the current region.' This clearly identifies the operation and distinguishes it from sibling tools like ncloud_get_cache_instance_detail (which fetches a single instance) and listing tools for other services.

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 implies usage context through 'List all' but provides no explicit guidance on when to use this tool versus alternatives. It does not mention that ncloud_get_cache_instance_detail should be used for a single instance, nor does it specify when not to use this tool. The context is clear but not explicit, so a score of 3 is appropriate.

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