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

The description usefully discloses side effects beyond the annotations: it creates the agent's competition sub-book, may deduct entry fees, and notes that launch competitions are free while USDC rail is parked. No contradiction with the idempotentHint/readOnlyHint annotations, though it doesn't state what happens if the agent is already entered.

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-loads the core action, then adds relevant side-effect and auth details. The phrase 'while the USDC rail is parked' is somewhat jargon-heavy but does not undermine an otherwise concise structure.

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?

Covers the ID source, side effects, possible cost, and authentication requirement. With only one parameter and no output schema, this is sufficient for invocation, though it does not mention what the agent receives back or how to handle the already-entered case.

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 documents competition_id as 'competition id from list_competitions,' and the description repeats that source. This is correct but not additive; no format, validation, or edge-case semantics are provided, so it meets the baseline without exceeding it.

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 opens with a specific verb and resource: 'Enter a paper-trading competition' and immediately identifies the required input from list_competitions. This clearly states what the tool does and separates it from read-only competition tools like get_competition_leaderboard.

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 tells the agent to use a competition_id from list_competitions)Skip? It gives clear context on when to invoke the tool. It does not explicitly discuss alternatives or say when not to use it, but the prerequisite and fee/rail context are enough for practical selection.

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