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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that a game is returned 'ready to play,' but it doesn't say what 'open' produces (a link, session, or launch payload) or what happens if the name/slug doesn't match.

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?

One short sentence with the action front-loaded and zero filler; nothing could be removed without losing information.

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 one-parameter tool with annotations and no output schema, the description is nearly sufficient, but the verb 'open' leaves the return behavior ambiguous — an agent cannot tell whether it receives a playable URL, a session handle, or an error on unknown input.

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 100% and the single 'game' parameter already carries an example. The phrase 'by its name or slug' restates the schema rather than adding format or matching rules beyond it, so baseline 3 applies.

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?

Specific verb+resource: 'Open one AGENTPARK game ready to play, by its name or slug.' It clearly differs from show_arcade (browse) and rate_game (feedback) by emphasizing opening a single game ready to play, though it never names those siblings explicitly.

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 — an agent infers this is the tool for launching a specific game rather than listing games or rating them — but there is no explicit when-to-use versus when-not guidance and no sibling is referenced.

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