hello_world

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

No annotations are provided, so the description carries the burden, but this is a benign, non-destructive greeting tool. The description is largely self-explanatory; there's minimal behavioral complexity. It doesn't describe the interactive UI's behavior (what happens when showUI is true), which is a minor gap, but acceptable for such a simple tool.

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?

Single sentence, zero waste. It front-loads the primary action ('Display a Hello World greeting') and appends the optional modifier. Every word earns its place.

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 2-parameter tool with 100% schema coverage and no output schema or nested objects, the description is complete enough. The main action, the resource, and the optional behavior are all covered. A more detailed description would be overkill for this level of simplicity.

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 both 'name' and 'showUI' having descriptions in the schema. The description adds the 'interactive UI' context that maps to the showUI boolean. With full schema coverage, the baseline of 3 applies; the description offers marginal additional semantic value.

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 states a specific verb+resource ('Display a Hello World greeting') with a clear modification ('with optional interactive UI'). It clearly communicates what the tool does, though it doesn't explicitly differentiate from the sibling tools (list_sort, flame_graph, feature_flags, database_query). The purpose is sufficiently distinct from siblings given their differing names.

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 implies its usage (displaying a greeting, optionally with UI), but provides no explicit when-to-use or when-not-to-use guidance, and no alternative suggestions. For a simple greeting tool, clear context exists, though no exclusions or alternative recommendations are offered.

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