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 'by country' scoping and says nothing about what an offer contains, whether results are provider-grouped, or how many countries are returned – a thin addition for a lookup tool.

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 short sentence with the resource and scope front-loaded and no filler. It is efficient, though the brevity tips toward under-specification rather than tight writing.

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 and annotations exist, so return values and safety need not be described. However, the description never clarifies what 'offers' means, nor that the required id must come from an episode-lookup tool, which an agent needs in order to invoke this 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 description coverage is 100%: the id format (tse[0-9]+), the language code, and the one-to-five country codes with defaults are all documented in the schema. The description adds nothing beyond that, so 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 phrase names a resource (JustWatch episode) and a scope (offers by country), so an agent can roughly tell it apart from justwatch_title_offers. But 'offers' is left undefined – it does not say these are streaming/rental/purchase availability listings – so the purpose is only partially pinned down.

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 at all: nothing says to call this after justwatch_episode_by_id, nor how it relates to justwatch_title_offers or justwatch_monetization_titles. The only implicit signal is the 'episode' qualifier in the name.

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