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 nothing beyond that: no note on whether url vs path resolves differently, no caching/rate-limit behavior, no indication that the response merges availability data from external providers.

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 fragment with no filler, front-loaded with the resource. It is efficiently sized, though it is so terse that it borders on under-specification rather than being a model of concision.

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, return values need not be explained, but the description still leaves the url-vs-path precedence, the relationship to justwatch_title_offers and justwatch_title_by_id, and the meaning of the combined 'details and offers' payload unresolved for a tool with readily confusable siblings.

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 both parameters (url, path) and the 'pass exactly one of path or url' constraint are already fully documented in the schema. The description adds no additional parameter meaning; 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?

States the resource (a JustWatch title) and the content returned ('details and offers'), which is more than a bare restatement of the name. However, it does not distinguish itself from immediate siblings like justwatch_title_by_id, justwatch_title_offers, or justwatch_title_analysis, so an agent cannot tell when this combined view is the right pick.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as justwatch_title_by_id or justwatch_title_offers. The agent must infer usage from the name alone.

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