aws_list_key_pairs

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

No annotations provided, so description carries full burden. It describes a read-only list operation without mentioning destructive behavior, auth requirements, or limitations. Adequate but could add details like 'returns all key pairs in the region' or 'no pagination.'

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?

Two sentences, no fluff. Every word serves a purpose, front-loading the core action and immediately providing actionable guidance for the agent.

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 a single parameter, no output schema, and no nested objects, the description is complete. It states the result contains key_name values and hints at their use. Could mention that it returns a list, but the implicit understanding is sufficient.

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 100% for the single 'region' parameter. The tool description adds no further detail beyond what the schema already provides ('AWS region (e.g. us-east-1)'). Baseline 3 is appropriate.

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 'List EC2 key pairs registered in the given region', using a specific verb and resource. It distinguishes from sibling tools like aws_list_amis or aws_list_security_groups, and adds context by noting the key_name values are used as argument to aws_run_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?

Description explicitly tells the agent to use the returned key_name values as input for aws_run_instances, providing clear context. While it doesn't mention when not to use, the purpose is straightforward and the hint about downstream usage is valuable.

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