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

With no annotations, the description carries the full burden, and it does add real value: the output is unsigned, the caller must sign and send it themselves, and cancel=true flips the operation into a cancellation. It omits prerequisites (wallet auth), whether an existing challenge must exist to cancel, and side effects of preparing, so coverage is partial.

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 tight sentences with the core action and the cancellation mode front-loaded, plus the workflow caveat. Every clause carries information; only the 'Fight Club:' prefix is filler.

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?

There is no output schema and no annotations, so the description is the only source of behavioral detail, and it covers the unsigned/self-sign workflow well. However, it leaves two of three parameters and any auth or preconditions undocumented, so an agent could still invoke it with an incorrect wallet/fighterId assumption.

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 0% across 3 parameters, so the description must compensate. It explains only 'cancel' (boolean, true means cancel); wallet and fighterId are left entirely to their bare names, which is inadequate for a 0%-coverage 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 and resource ('prepare (unsigned) a challenge') scoped to 'one of your fighters', and the 'Fight Club' prefix places it in a clear product domain. It implies the prepare/self-sign pattern shared with sibling tools like prepare_accept and prepare_bet, though it never names them explicitly, so sibling differentiation is inferred rather than stated.

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?

It gives implied usage (use this to create a challenge; set cancel=true to cancel one) and clarifies the follow-up workflow ('You sign and send it yourself'). It does not say when to use this versus open_challenges, prepare_accept, or other prepare_* siblings, leaving alternatives to inference.

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