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

The annotations already mark this as read-safe, and the description adds substantial behavioral context beyond that: results are ranked, the top section uses scarcity evidence like measured seat counts and final nights, and detailed mode exposes confidence levels, source tier, and verified_at. This gives the agent a realistic picture of answer behavior before invoking.

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 dense but front-loaded: the core ranked-list purpose is in the first clause, and each later clause adds a new configurable point (windows, filters, Notable tonight, entry fields, detailed mode). It is long but not bloated, and 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?

Given all parameters are optional, all are schema-description covered, and an output schema exists, the description completes the picture well: it covers window semantics, ranking behavior, both modes, distinct scarcity evidence, and exact entry fields. Nothing essential for the agent to call it correctly appears missing.

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%, and each parameter already has a useful description, enum, or default. The description recaps genre/format filters and explains 'detailed' mode a little, but does not meaningfully expand on parameter syntax beyond what the schema already provides, 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 description states a concrete output: 'Ranked list of films playing San Francisco theaters in a given window' and enumerates filters, ranking, and entry fields. It is clearly a discovery/list tool, but it does not explicitly differentiate itself from siblings such as scenef_search_showtimes or scenef_now, so it misses the full sibling-contrast criterion for a 5.

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?

It gives useful context about when the 'tonigth/tonight' window triggers 'Notable tonight' and advises to lead with those when asked what to see. However, it never says when not to use this tool or mentions any sibling alternative (search, coming soon, theater info), so the guidance is reasonably impliesed rather than explicit.

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