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

Annotations already declare destructive=true, readOnly=false and openWorld=false, so the safety profile is covered; the description adds genuinely new context about billing settlement and the return of an unused reservation, plus how a repeated stop behaves. The only gap is that the stated repeat behavior sits in mild tension with idempotentHint=false, and error/precondition cases are not described.

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?

Two sentences, zero filler, and the primary action plus its most important consequence (billing settlement) is front-loaded before the repeat-call nuance.

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 mutation tool with no output schema and no param documentation, the description covers the key business consequence but omits preconditions, failure modes, and what a settled session leaves behind. Adequate but with clear gaps given the complexity of billing settlement.

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% for two required parameters (workspaceId, avatarSessionId) and the description says nothing about either — no format, no pattern, no hint about where the session id comes from. Parameter names are largely self-explanatory, which keeps this from being a 1, but the description does not compensate for the coverage gap.

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 (stop) plus resource (avatar session) and even names the side effect (settling connected-time billing). It is unambiguously the teardown counterpart to start_live_avatar_session and quote_live_avatar_session, so an agent can pick it without opening any schema.

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?

Usage is implied by the verb and by the sibling set (you stop a session that was started), and the repeat-call behavior is stated. But there is no explicit when-to-use/when-not guidance, no mention of prerequisites (e.g., session must be active) and no named alternatives.

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