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

With no annotations, the description carries the full burden and does so well: it discloses that resends are permitted, that only the latest answer per task before close is scored, the three scoring modes (exact match, numeric tolerance, file hash), the practice-round exclusion, the 20-answer cap, and the api_key auth requirement.

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?

Information-dense with the key constraint (before close) and payload format front-loaded, and every clause carries meaning. It is slightly crammed into long sentences, but there is little outright waste.

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 mutation tool with no annotations and no output schema, the description covers submission timing, resend behavior, scoring, and auth well. It omits error/failure behavior and whether league/round must match a prior registration, which are minor but real gaps.

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 coverage is only 20%, so the description must compensate and partially does: it explains the answers shape '{task_id: answer}', the cap of 20, and that api_key is the bot's credential. League, round, and agent_id are left unexplained beyond their names and the enum list, leaving real gaps.

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 ('submit answers for a round') plus the scoping condition 'before it closes', which cleanly separates it from sibling write tools like arena_submit_weights. An agent can identify the action and the payload shape immediately.

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?

Gives clear context for use: submit before round close, resend is allowed, and practice rounds are explicitly excluded ('never count'). It does not name a sibling alternative or prerequisite ordering (e.g. call arena_round_tasks first), so it falls short of a full when/when-not rubric.

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