Discover movies or TV shows

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety and determinism profile is covered. The description adds no behavior beyond the annotation layer - nothing about pagination limits, default sort semantics, or how streaming availability is resolved per region. With annotations present the bar is lower, so 3 is appropriate.

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, zero filler: the first defines the criteria-based mode and the second gives a concrete usage example. Front-loaded with the distinguishing concept rather than burying it.

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?

For a 13-parameter tool with an output schema available, the description covers the discovery-facing filters well enough to call it correctly. The gaps are on the control parameters (mediaType default of "movie", sortBy, page, excludeGenres), which matter for a broad-discovery tool but are partially recoverable from schema defaults and enums.

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 only 46%, so the description usefully compensates by enumerating the main filters (genres, year range, minimum score, max runtime, original language, streaming service, region) and giving value examples like "sci-fi" and "Netflix" that the schema lacks. It still leaves page, sortBy, mediaType and excludeGenres entirely unaddressed.

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?

"Find titles by criteria instead of by name" is a specific verb+resource that draws a clean line against the name-based search siblings (search_movies, search_tv_shows), and the enumerated criteria show the shape of the query. It stops short of 5 because it never names a sibling and never explains that this single tool covers both movies and TV while the siblings split them.

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 closing sentence gives an explicit positive trigger ("a good 90s thriller on Netflix under 2 hours") plus the implicit negative case (name-based lookup belongs to the search_* tools). There is no explicit "do not use for person lookups / details" routing despite four detail and people-oriented siblings.

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