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

With no annotations, the description carries the full burden. It does add genuine behavioral value with the scoring formula (Score = 100 - |guess - actual|) and the statement that full results are returned, but it omits auth requirements, whether a guess is final/resubmittable, and any rate or eligibility limits.

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?

Three short sentences, front-loaded with the purpose, followed by the scoring rule and return behavior. Nothing is padded and each clause earns its place.

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?

No output schema, no annotations, and 5 params at 40% coverage mean the description should do more. It omits auth/token flow, prerequisites for obtaining IDs, and submission constraints, which an agent needs to invoke this game tool correctly.

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 40% (locale and agent_token documented; question_id, option_id, world_percent not). The description partly compensates by framing world_percent as a 0-100 percentage and linking question_id/option_id to "yesterday's question," but it says nothing about locale or the agent_token requirement, 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 (guess) and resource (world percent for an option of yesterday's question), and the scope "yesterday's question" implicitly separates it from answer_today and get_today_question. However, it never names a sibling, so the differentiation is left for the agent to infer.

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?

The purpose wording implies the use case (submit a guess for yesterday's question), but there is no explicit when-to-use guidance, no mention of prerequisites such as first calling get_yesterday for the question_id/option_id or register_agent for the token, and no when-not guidance.

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