get_player_stats

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

With no annotations provided, the description carries the full burden for behavioral transparency. It indicates a read operation ('Get') but does not disclose any additional behavioral traits such as authentication requirements, rate limits, or whether the data is real-time. For a simple read tool, this is minimally adequate but lacks depth.

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 a single, front-loaded sentence: 'Get a Chess.com player's ratings and win/loss statistics.' It is concise and contains no unnecessary words, earning the highest score.

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 the tool's simplicity (one parameter, no output schema), the description is mostly complete: it states what the tool retrieves (ratings and win/loss stats). However, it does not elaborate on the exact structure of the return value or any caveats (e.g., historical vs. live data), which would be helpful given the absence of an output schema.

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 schema already provides a complete description of the single parameter (username with pattern and description). The description adds no additional parameter semantics beyond what the schema covers, so the baseline score of 3 is appropriate.

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 identifies the tool's function: 'Get a Chess.com player's ratings and win/loss statistics.' This specifies a verb ('Get') and a specific resource (player's ratings and win/loss stats), distinguishing it from sibling tools like get_player_profile (profile info) and get_player_games (game history).

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?

The description implies usage for retrieving ratings and win/loss statistics, but it does not explicitly state when to use this tool over alternatives or provide exclusions. There is no guidance comparing it to sibling tools like get_player_profile or get_player_games.

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