list_buckets

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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly states the default provider behavior when provider_id is omitted, which is a meaningful side effect not captured in the schema. The read-only nature is implied by 'List', but details like pagination or error handling are not disclosed, preventing a score of 5.

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 consists of two sentences with no redundancy. The main action is front-loaded, and the parameter documentation is concise, making it easy to parse quickly.

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 one optional parameter and an output schema, the description covers the essential behavior and parameter semantics. The output schema handles return value details, so the concise description is fully adequate.

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 description adds essential meaning to the single parameter provider_id, calling it an 'Optional connection ID of the provider' and explaining its role in deciding which provider to use. This goes well beyond the schema, which only indicates type and default without any semantic explanation.

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 all S3 buckets' with an optional provider scope, which is specific and actionable. It distinguishes from sibling tools like list_bucket_objects (objects within a bucket) and list_providers (providers themselves).

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 explains how to use the optional provider_id ('for a specific provider, or the default provider if not specified'), which gives some usage context. However, it does not explicitly mention when to prefer this tool over alternatives like list_bucket_objects, leaving the comparison to implication.

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