Where to watch

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint), but the description adds two things they cannot: the upstream data provenance (JustWatch) and a compliance requirement to attribute that source to users. It still says nothing about caching, freshness, or rate limits on a third-party data source.

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 sentences, no filler, with the core capability front-loaded and the attribution obligation as a short trailing sentence. Every sentence 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?

An output schema exists, so return values need not be explained, and the description covers scope, region granularity and the source. The remaining gap is relational: it never tells the agent how this complements get_movie_details or that a media id must be obtained first.

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 67% and the schema itself documents id (TMDB id), region (ISO 3166-1 with default) and the mediaType enum. The description only echoes the concepts of country and movie/show, adding no syntax or format detail beyond the schema, so baseline 3 is appropriate.

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 concrete resource and outcome: where a movie or show can be streamed, rented or bought in a country. That clearly separates it from search_movies, get_movie_details and the other discovery siblings, though it uses a noun phrase rather than an explicit verb and never names a sibling.

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?

There is no when-to-use guidance, no statement of prerequisites (a TMDB movie/TV id is required), and no differentiation from get_movie_details, which an agent might reasonably assume also carries provider data. The only usage-like instruction concerns displaying the source, not selecting the tool.

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