list_supported_providers

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

There are no annotations, so the description carries the behavioral burden. The verb 'list' signals a read-only operation, but the description does not add context about whether authentication is required, whether the list is static or dynamic, or what the output structure looks like. It is minimally transparent but lacks depth.

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 a single, short, front-loaded sentence that names the action and the resource with no wasted words. It is appropriately sized for such a simple tool.

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—zero parameters, no output schema, and a narrow purpose—the description is sufficiently complete for an agent to select and invoke it correctly. It clearly states what will be returned conceptually (the list of supported email providers), though a bit more detail about the result format would have pushed it to a 5.

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 tool has zero parameters and the schema coverage is effectively complete, so the description does not need to explain parameter behavior. The baseline for no parameters is 4, and the description correctly avoids inventing unnecessary parameter details.

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 uses the specific verb 'list' with a clear resource ('supported email providers'), which exactly matches the tool name and distinguishes it from the sibling tools that send, fetch, set up, configure, or test. An agent can immediately understand what this tool does and why it exists.

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 clearly implies this is the tool to call when an agent needs to know which email providers are available. It does not explicitly mention when not to use it or name alternatives, but none of the sibling tools perform this listing function, so the context is clear enough with no real exclusions needed.

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