Discover movies (filters)

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the tool's safety and open-world nature are known. The description does not contradict these and adds that the tool queries by filters. However, it does not discuss rate limits, pagination details, or result format beyond what the schema provides. For a read-only query tool, the description is adequate but not exceptional.

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?

The description is two sentences: the first lists all filter categories, the second provides a concrete use-case example and hints for resolving IDs. Every part is useful, no wasted words, and the most critical information (purpose and example) comes first.

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?

Given the high parameter count (24) and no output schema, the description covers the essential: what filters exist and how to use them (via example and ID resolution tips). It lacks mention of pagination (page param) and dependencies like certification_country, but the schema covers those. For a query tool with many optional filters, the description is sufficiently complete.

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?

The input schema has 100% coverage with descriptions for all 24 parameters. The tool description lists categories of filters but does not add meaning beyond the schema, such as clarifying that with_genres uses AND logic or that certification requires certification_country. The baseline for high coverage is 3, and the description does not elevate beyond that.

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 clearly states the tool finds movies by structured filters, not by title. It lists many filter types and gives a concrete example ('popular sci-fi from the 1990s rated above 7 available on Netflix'). It distinguishes itself from the sibling tool discover_tv (for TV) and implicitly from search_movies (title search).

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 description advises to use this tool for filter-based discovery and tells users to resolve IDs with get_movie_genres, search_people, and search_keywords. It does not explicitly mention when not to use it (e.g., for title search use search_movies instead), but the example and context provide clear guidance.

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