s3_create_bucket

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

Discloses cost implications and need for confirmation, which is critical for a creation tool. No annotations exist, so description carries the behavioral burden well, though could mention error states or permissions.

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?

Three concise sentences, front-loaded with primary action, followed by critical warnings. Every sentence provides essential information without redundancy.

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 (two parameters, no output schema, no annotations), the description covers key aspects: creation, cost, danger, and confirmation. Lacks guidance on idempotency or error handling, but sufficient for most cases.

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 100% with descriptions for both parameters. Description adds no additional semantic value beyond schema, but includes an extraneous mention of 'region' which is not a parameter, causing potential confusion. Baseline 3 maintained.

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 creates a new S3 bucket. It uses specific verb 'Create' and resource 'S3 bucket', and distinguishes from sibling tools like s3_delete_bucket and s3_list_buckets.

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?

Explicitly warns of cost ('billing starts immediately'), danger ('Reserved for dangerous guard mode'), and requires user confirmation. Provides clear context on when and how to use, though does not specify alternatives.

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