Play history

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful context: the records are Zaparoo's own and include games launched from the MiSTer menu (a non-obvious inclusion rule), plus that rows carry a ref. It says nothing about ordering guarantees across modes or result limits, so it adds value but stays thin.

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, front-loaded with the scope, and every clause carries information (data source, menu-launch inclusion, ref for replay). The conversational phrasing ('play the last thing again') is slightly informal but not wasteful.

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 an output schema present and annotations covering read-only semantics, the description only needs to frame the data and its quirks; it does that by explaining provenance and the ref field. Minor gaps remain around mode-specific behavior and limits, but nothing blocks correct 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?

Schema coverage is 75% and the schema already explains host, mode ('recent' vs 'top'), and system with examples. The description only contributes the ref/host interaction obliquely; it adds no syntax or semantics for limit or mode beyond what is structured.

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 opening clause names the resource and scope concretely ('what's been played on each MiSTer') and adds the data source ('Zaparoo's own records'). It is clearly a read/history query, distinct from launch or get_status, though it never names a sibling to contrast with.

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 only implied: 'play the last thing again' hints at the replay workflow via launch, and the host parameter note says to omit it when a ref already identifies the host. There is no explicit statement of when to choose recent vs top, or when to prefer this over search_games.

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