ncloud_serverless_list_instances

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

The readOnlyHint annotation already establishes the operation is read-only. The description adds behavioral detail beyond that: it names the HTTP GET endpoint, the returned fields, and the valid sort fields, which helps the agent understand what to expect. It does not contradict annotations.

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 concise sentences, with the purpose stated first and supporting details (endpoint, return fields, sort fields) immediately following. No redundancy or filler.

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 straightforward list operation with no output schema, the description covers the essential return fields and sort options. Pagination parameters (pageNo, pageSize) and clusterName are documented in the schema with defaults and constraints. Nothing an agent needs to call it correctly is missing.

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% for all parameters, so the baseline is 3. The description adds value by explicitly enumerating the allowed sort fields (name, role, zoneCode, createdDateTime), which the schema only references generically as 'allowed fields per tool'. This is useful extra information for constructing the sort parameter.

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 verb (List) and the resource (instances of a Cloud DB Serverless cluster), and includes the HTTP endpoint. It also lists the returned fields (role, unit, memoryGb, etc.), which makes the tool's purpose unambiguous and distinct from related tools like get_instance (single) or list_clusters.

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?

Usage context is implied: it lists instances for a given cluster, and the required clusterName is indicated. However, there is no explicit comparison to alternatives such as ncloud_serverless_get_instance (to fetch a single instance) or ncloud_serverless_list_clusters (to list clusters), nor any when-not-to-use guidance. This leaves selection mostly to inference.

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