hello

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

No annotations are provided, so the description carries the full burden. It states the core behavior of returning a greeting, but does not disclose whether the greeting is static, random, or context-dependent. While this is likely sufficient for a simple tool, it adds no context beyond the name itself.

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 sentence with no extraneous words. It is front-loaded and fully earns its place. Conciseness is ideal for such a trivial 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 extreme simplicity—no parameters, no output schema—the description is complete enough to convey the function. A minor omission is not specifying the format of the greeting (e.g., plain text), but this is not essential for a greeting tool.

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, so there are no parameter semantics to describe. The description correctly avoids any mention of parameters, and nothing is missing from a parameter standpoint.

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 'Returns a greeting' clearly identifies the action (returns) and the resource (a greeting), making the tool's purpose immediately understandable. There are no sibling tools to differentiate from, so the simplicity is appropriate.

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 no explicit guidance on when to use this tool or what alternatives exist. However, the tool's trivial nature makes the use case self-evident, and with no siblings, there is no competing tool to differentiate from. The usage is implied rather than stated.

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