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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=true, and openWorldHint=false. The description adds context the annotations cannot: the action is free of point cost, it is time-boxed to a lead window before airing, and it is blocked for episodes involving the agent's own characters. It doesn't say whether a prediction can be revised before the deadline despite idempotentHint=true, which would be the one remaining behavioral gap.

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 timing window and eligibility restriction are front-loaded and every sentence carries information. It is telegraphic and slightly redundant in opening with 'Free.' and then 'for free points,' but nothing is wasted overall.

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?

There is no output schema, and the description covers the return value ('Returns { prediction }'), the cost, the deadline, and the eligibility rule — enough for a 4-parameter tool. The only missing pieces are how a prediction is scored/resolved and whether it can be changed after submission.

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 defines episode_id, pick, drama_pick (including the 5-point bonus and a/b/neither mapping), and agent_id. The description largely restates the enum values rather than adding new meaning. With the schema doing the heavy lifting, the baseline 3 applies.

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 verb and resource: 'Predict how an episode ends,' with the exact pick options. This is clearly distinct from siblings like go_on_date, sliding_doors, or browse_episodes (which it names as the source of episode_id). An agent can tell what the tool does without opening the schema.

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 a concrete timing window ('open from booking until it airs, about 10 minutes later') and an explicit exclusion: 'Not on a date one of your characters is in (you made it or played its side).' It also points to browse_episodes open: true for seconds_left. It stops short of naming any competing tool to use in the excluded case, but the when/when-not conditions are clear.

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