steam_get_global_achievement_stats

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does reveal output content (10 easiest/hardest achievements with unlock percentages), but it is ambiguous: first saying 'all achievements' and then '10 easiest and 10 hardest.' It also omits response format details and edge cases.

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 description is short and front-loaded with the primary action, but there is minor redundancy between 'global completion rates' and 'global unlock percentages,' and the standalone sentence 'Accepts a Steam AppID' adds little beyond the schema.

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 one-parameter tool with no output schema, the description gives adequate high-level information. However, it leaves unresolved whether the tool returns all achievements or only the 10 easiest/hardest, and it does not address error conditions or output structure.

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?

The input schema already provides 100% coverage with the description 'Steam AppID' for the appid parameter. The tool description merely repeats this and adds no additional constraints, formatting details, or usage nuances beyond the schema.

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 clearly states it 'Returns global completion rates for all achievements in a game' and specifies the output includes the 10 easiest and 10 hardest achievements with percentages. The term 'global' effectively distinguishes it from sibling tools like steam_get_achievements, which are player-specific.

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?

Provides an explicit use case: 'Useful for understanding how rare an achievement is across all players.' However, it does not mention when to prefer alternatives or give any exclusion criteria, so it stops short of full guidance.

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