Show emoji

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the mutation/safety profile is covered. The description adds the useful 'none hides it' behavior, but says nothing about what happens to prior screen content, whether a connection is required, or the effect of repeated calls.

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?

A single efficient sentence with the core action front-loaded and the special-case value appended in parentheses. No wasted material, though it is arguably under-specified rather than genuinely concise.

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?

With only two enum parameters, no output schema, and safety already covered by annotations, the definition is close to adequate. However, it omits any meaning for 'look' and gives no hint of the mutation's effect or return, leaving a real gap for a screen-state-changing 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?

Schema description coverage is 0%, so the description must carry parameter meaning. It clarifies that 'none' hides the emoji, but the 'look' parameter (forward/left/right) is never explained, leaving one of two parameters undocumented in both schema and description.

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?

States a specific verb ('Show') and resource ('the robot's animated faces on its screen'), so an agent can tell this apart from show_text or set_lights by the visual-face emphasis. It does not explicitly name a sibling, but the purpose is unambiguous.

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?

No when-to-use guidance, no mention of alternatives (e.g., show_text vs show_emoji), and no stated preconditions such as needing an active connection. The agent is left to infer usage entirely from the purpose line.

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