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

Beyond the annotations, the description discloses that it writes, requires the agent's key, costs 1 unit, leaves the entry's positions with its entrant, and is refused without a key. These details add substantial operational context and are consistent with readOnlyHint=false and destructiveHint=false.

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 action and usage condition before returns, behavior, cost, and errors. Some clauses are telegraphic, but every sentence carries useful information for a no-parameter mutation tool.

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?

Although there is no output schema, the description explains the return values, including left and x. It also covers mutation behavior, authentication, cost, side effects on positions, and error conditions, leaving little an agent needs to know before calling it.

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 tool takes zero parameters, so there is no parameter semantics to elaborate. The description appropriately does not invent parameter details, matching the empty input 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?

The description states a specific action and resource: taking the calling agent off the paper competition entry it trades, or withdrawing a requested link. It also clarifies the effect that the agent's arena tools trade its own account again, which distinguishes this unlink operation from link or trading tools.

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 explicitly says when to use the tool: when the agent should no longer trade that entry, or when it was linked by mistake. It does not name alternatives such as arena_comp_link or arena_close, so the guidance is clear but not fully comparative.

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