db_create_read_replica

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 states the operation (create) and lists parameters, but does not disclose side effects, cost implications, replication lag behavior, whether the source database is affected, or any constraints (e.g., region must match source, plan compatibility). For a mutation tool with zero annotation coverage, this is a significant gap.

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 compact and front-loaded with the core purpose. The Args/Returns structure is scannable and each line earns its place. It could be slightly more concise by dropping the 'Returns' section since an output schema exists, but it is not bloated.

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?

The tool has an output schema, so return values are covered. However, with no annotations, no parameter enums, and 0% schema description coverage, the description must provide more context about prerequisites, constraints, and side effects. It does not mention that the source database must exist, whether the replica is created asynchronously, or any region/plan compatibility rules. For a create operation with four required parameters, this is 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?

Schema description coverage is 0%, so the description must compensate. It lists the four parameters with one-line meanings ('The source database ID or label', 'Label for the read replica', etc.), which adds some value beyond the bare schema. However, it doesn't explain formats, constraints, or how to obtain valid values (e.g., where to find plan IDs, region names). The coverage is minimal and leaves the agent guessing about valid inputs.

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 a specific verb and resource: 'Create a read replica of a database.' This clearly distinguishes it from sibling tools like db_create, db_fork_database, and db_promote_read_replica. However, it doesn't explicitly name those siblings or contrast itself with them, so it falls short of a 5.

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: it is for creating a read replica, which is distinct from creating a database (db_create), forking (db_fork_database), or promoting a replica (db_promote_read_replica). But it provides no explicit guidance on when to choose this tool over alternatives, no prerequisites (e.g., source database must exist), and no exclusions. The context is clear enough to infer, but not explicitly stated.

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