Get current player count

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

Discloses beyond annotations: works without a key, errors clearly on invalid appid. Annotations already indicate readOnly and openWorld, so description adds useful context without contradiction.

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, no wasted words. Front-loaded with the main purpose, concise and effective.

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?

Given a simple tool with full schema coverage and an output schema, the description covers prerequisites, error handling, and authentication requirements completely.

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 100% with a description for appid, so baseline is 3. The description adds 'Get the appid from search_games' (redundant) and error behavior, but does not significantly enhance parameter semantics beyond 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 the verb 'Get' and the resource 'how many people are playing a game right now (live concurrent player count)', and distinguishes it from sibling tools like search_games (to obtain appid).

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?

Specifies that appid is obtained from search_games and mentions the tool works without a key, but does not explicitly exclude scenarios or provide alternative tools for similar tasks.

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