describe_db_instances

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

Annotations already declare readOnlyHint=true, so the description adds no extra behavioral context (e.g., pagination, error handling). It merely restates 'queries' without revealing limitations or side effects.

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 very brief but lacks structure: an incomplete 'Args:' section and empty ':return:' make it feel unfinished. It is not front-loaded with a clear summary.

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 list-like operation with no output schema, the description omits what is returned (e.g., instance IDs, statuses). This leaves the agent uncertain about the tool's output, making it incomplete.

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?

With 0% schema description coverage, the description partially compensates by explaining 'region_id: queries instances in region id(e.g. cn-hangzhou)', but it lacks format, constraints, or default behavior. Minimal value added.

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 states 'Queries instances', which identifies the verb and resource, but lacks specificity: it does not clarify that these are database instances, nor does it differentiate from sibling tools like describe_db_instance_attribute.

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?

No guidance on when to use this tool versus alternatives is provided. The description does not mention prerequisites, exclusions, or context for selection among the many describe siblings.

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