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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the ranking metric (peak concurrent players) and the weekly cadence, but says nothing about pagination, row counts or freshness beyond the period, so it adds only modest context.

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. The purpose and ranking basis come first, the disambiguation second, which is the right front-loading for selection.

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 safety, the description only needs to nail purpose and routing, which it does. The minor gap is that all three optional enrichment parameters go unmentioned, leaving the agent to rely purely on the schema for tuning output.

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 all three parameters (l, cc, enrich) are documented there, so the baseline of 3 applies. The description never mentions language, country enrichment, or the enrich flag, so it contributes no meaning 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?

States a specific verb, resource and ranking basis: the weekly most-played chart ranked by peak concurrent players. It also names the three sibling tools it is not, so an agent can separate it from steam_charts_concurrent, steam_charts_top_releases and steam_top_sellers 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?

Gives explicit routing: use steam_charts_concurrent for concurrent-user snapshots, steam_charts_top_releases for new releases, steam_top_sellers for sales rankings. Both the when-to-use and the alternatives are stated outright rather than implied.

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