describe_db_instance_databases

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

The description adds context beyond annotations by noting it operates in batch and returns a list of dicts. However, with readOnlyHint already present, it adds limited behavioral detail such as performance implications or response structure.

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 extremely concise: a single sentence for purpose, then straightforward parameter definitions. Every piece of text is valuable and front-loaded.

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 (2 required parameters, output schema exists), the description provides enough context. It explains the batch nature, parameters, and return format, though it could briefly note that details are in the output schema.

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 coverage, the description significantly adds meaning by specifying region_id as the region ID and providing an example for db_instance_ids. This compensates for the lack of schema descriptions.

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 performs a batch retrieval of database information for multiple RDS instances, using specific verbs and resource. It distinguishes itself from sibling tools like describe_db_instances by focusing on databases within instances.

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 no guidance on when to use this tool versus alternatives (e.g., describe_db_instances for instance metadata). It only states what it does, leaving the agent to infer usage context.

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