create_challenge

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

With no annotations, the description carries full burden but only states the action without behavioral details. It doesn't disclose outcomes (e.g., sends a challenge request, may be declined), permissions needed, rate limits, or side effects. This is inadequate for a mutation tool with potential user interactions.

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, efficient phrase with zero waste—it directly states the tool's action. It's appropriately sized and front-loaded, making it easy to parse without unnecessary elaboration.

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 tool with 7 parameters, no annotations, and no output schema, the description is incomplete. It doesn't explain what happens after challenging (e.g., challenge ID returned, notification sent) or address behavioral aspects like error conditions. Given the complexity, more context is needed.

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%, so parameters are well-documented in the schema. The description adds no parameter semantics beyond implying a 'username' is involved. This meets the baseline of 3, as the schema handles the heavy lifting, but the description doesn't enhance understanding.

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 'Challenge another player' clearly states the action (challenge) and target (another player), but it's vague about the context—it doesn't specify this is for initiating a chess game or differentiate it from sibling tools like 'create_arena' or 'create_simul' for other game formats. It avoids tautology but lacks specificity.

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?

No guidance is provided on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., the user must be logged in), exclusions (e.g., cannot challenge oneself), or compare to siblings like 'accept_challenge' or 'cancel_challenge'. The description alone offers no usage context.

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