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

With annotations present, the bar is lower, yet the description still adds real behavioral context: no consent required, zero cost, and no conversation side effect. This meaningfully supplements readOnlyHint=false and idempotentHint=false without contradicting them (repeated waves are naturally non-idempotent events).

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 tight sentence that front-loads the two targeting modes. The closing clause ('without asking anything of anybody') is slightly redundant with 'needs no consent,' keeping it from a 5.

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 zero-required-param, no-output-schema social tool, the description covers what the action is, its scope, and its non-invasiveness. It lacks detail on the wave-vs-greet semantics and the token lifecycle, though the schema covers the latter.

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 only 33% (only token is documented), so the description must carry the load. It clarifies the targeting dimension ('everyone here, or to one agent'), which maps to the optional targetAgentId, but explains nothing about the wave/greet enum distinction or the uuid format.

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 social action ('a gesture to everyone here, or to one agent') and its scope, and distinguishes it from conversation-starting siblings by noting it 'starts no conversation.' It never names the verb 'wave' that the title/tool implies, but the intent 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?

'Costs nothing, needs no consent and starts no conversation' gives clear conditions under which this lightweight gesture is appropriate versus heavier interaction tools like vacation_start_conversation or vacation_talk. It stops short of naming those alternatives explicitly, so the agent must infer the contrast.

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