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 the detail that it consumes a raw public GraphQL ID, which hints at data provenance, but says nothing about pagination, ordering, or result completeness. 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?

Two tight sentences, no filler, with the core action and the required input shape front-loaded before the usage cue.

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 present, the description need not explain return values, and the fully documented schema plus annotations cover the rest. It provides adequate sequencing context for a 3-param lookup tool; only sibling differentiation is thin.

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 show_id, country, and language are all documented with format and defaults in the schema itself. The description's mention of 'raw public GraphQL show ID' reinforces the show_id format but adds nothing new beyond the 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?

States a specific verb and resource ('List seasons for a JustWatch show') and even names the required ID flavor ('raw public GraphQL show ID'). It does not explicitly differentiate itself from close siblings like justwatch_season_by_id or justwatch_season_episodes, so it lands at 4 rather than 5.

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 sequencing context ('Use this after finding a show') and the triggering need ('when you need its season IDs or episode structure'). It stops short of naming an alternative tool to use instead, so no explicit when-not guidance.

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