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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only that offers are 'normalized', with no mention of pagination, how country/language shape results, or rate limits — modest added value over the annotations.

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?

A single front-loaded sentence with no filler or repetition. Appropriately sized for a simple read tool, though it could carry one more clause of routing guidance without bloat.

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?

With an output schema covering return values and annotations covering safety, the main remaining gap is routing: the description doesn't say when to prefer this over sibling season/episode tools. Adequate but with a clear gap.

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 documents country, language, and the tss[0-9]+ season_id format. The description adds no syntax or format meaning beyond what the schema provides, so the baseline of 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?

States a specific verb (Returns) and resource (episodes and normalized episode offers) scoped to a JustWatch season id. Clear enough to distinguish from justwatch_season_by_id or justwatch_episode_offers, but it never names a sibling or explicitly contrasts scope.

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 phrase 'for a JustWatch season id' implies a season id is needed, but there is no guidance on when to use this versus justwatch_season_by_id, justwatch_episode_offers, or where the season id comes from (e.g., justwatch_show_seasons). Effectively no when-to-use or exclusion guidance.

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