list_aws_reserved_instances

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description doesn't need to restate that. It adds significant value by disclosing pagination behavior and the filtering capabilities. This exceeds the baseline for what annotations provide, giving context on the response's pagination contract.

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 concise and front-loaded with the purpose, followed by filtering and pagination guidance in a single paragraph. Every sentence adds value, with no redundant or filler content. It is appropriately sized given the complexity.

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 complexity (10 params, no output schema) and good annotations, the description covers the essential aspects: purpose, filters, and pagination. It doesn't explain return format details, but since there's no output schema and the pagination contract is described, it's complete enough for a read-only list endpoint.

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 very low at 10%, so the description partially compensates by listing filterable dimensions (state, instance type/family, region, offering class) that map to parameters. However, it doesn't elaborate on the meaning of each parameter beyond what's in the schema, and some parameters like customerContext are not described here. The description adds some value over the minimal schema but doesn't fully compensate for the lack of individual parameter 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 'Returns the paginated list of Reserved Instances (RIs) for the specified organization,' combining a specific verb with a resource and scope. It also differentiates from siblings like list_aws_savings_plans and list_aws_planned_purchases by naming the resource type.

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 clear context for pagination usage, explaining how to fetch subsequent pages via the pageToken parameter and when to stop. However, it does not explicitly state when not to use this tool or mention alternatives, though the pagination guidance is useful for usage.

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