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

The description adds useful behavior beyond the idempotentHint annotation: public games appear in the Explore gallery, private games are owner-only, and private requires a paid plan. It does not disclose permission requirements, whether exposing a game to Explore is irreversible, or what happens to existing access when switching to private.

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 definition is a single compact sentence with no filler, and the most important value distinction is front-loaded. Nothing is repeated from the schema or annotations.

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 two-parameter mutation tool with no output schema and minimal annotations, the description covers the main enum semantics and plan constraint. It still omits the explicit action, authorization rules, and side effects of changing visibility, which are important for safe invocation.

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?

With 0% schema description coverage, the description compensates well for the visibility enum by explaining both values and the paid-plan condition. However, it adds no meaning for the required game_id parameter, even though its intent is mostly obvious from the tool name.

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 explains what public and private mean in this context, but it never explicitly states that the tool sets a game's visibility. The action is implied by the tool name and title rather than clearly expressed, and no sibling differentiation is provided.

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 only guidance is that private visibility requires a paid plan. It does not say when to choose public versus private, who is allowed to make this change, or how this differs from any alternative workflow.

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