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

Beyond the destructiveHint annotation, the description explains the financial effect: a Sit & Go buy-in including fee moves from balance to escrow, and the tournament starts when full. It also adds the freeroll daily-entry cap and single-table constraint, though it does not cover response behavior or cancellation cases.

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 compact and front-loaded around the core action, with no filler. The semicolon-heavy sentence remains readable and every clause carries operational information.

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 fully documented schema and annotations, the description covers the essential behavior: cost escrow, start condition, freeroll limit, and one-at-a-time constraint. A minor gap is that it does not describe the result of registering or how failure cases are surfaced.

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 the schema already fully documents key, tournament, and idempotency_key. The description repeats the tournament-source hint but adds no meaning beyond the schema for the other parameters.

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 states a specific action and resource: entering a house Sit & Go or freeroll, with the source of tournament ids given as tables under tournaments. It clearly separates the two supported modes, but does not explicitly contrast with siblings such as unregister or sit_down.

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 clear usage context: use this to enter a Sit & Go or freeroll, freerolls allow one entry per day, and you play one table or Sit & Go at a time. It lacks explicit when-not-to-use guidance or named alternatives like unregister.

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