list_sql_instances

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

The annotations already cover the safety profile with readOnlyHint, idempotentHint, and destructiveHint, lowering the bar. The description adds a note about environment scoping but does not disclose return format, pagination, or default-environment details. It neither contradicts the annotations nor provides substantial additional behavioral context.

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: one direct purpose sentence followed by terse, meaningful parameter explanations. There is no filler or redundant restatement of the schema.

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 with two optional parameters, strong annotations, and no nested schema, the description is sufficient. It documents both parameters and their defaults, and the safety profile is already carried by the annotations, so nothing needed to invoke the tool 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?

The input schema provides no parameter descriptions, so the description carries full responsibility. It compensates well: 'limit' is defined as the maximum number of instances, and 'environment' is explained with concrete examples and explicit default behavior.

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 opens with a specific verb and resource, 'List Cloud SQL instances,' which clearly identifies the operation. It is readily distinguishable from sibling list tools such as list_compute_instances and list_gke_clusters because the resource is explicitly named.

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 usage context is implied by the verb-resource pairing: this is the tool to call when enumerating Cloud SQL instances. However, it does not explicitly state when to prefer this tool over alternatives or when not to use it, so it earns only an implied-usage score.

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