What's playing in SF

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

Annotations already mark this as read-only and non-destructive, and the description adds substantial behavioral detail: the 'Notable tonight' lead section, evidence types like measured seat counts and lone prints, per-entry fields, and the extra metadata available in detailed mode. There is no contradiction with the annotations.

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 and front-loaded: the first sentence states the core purpose and scope, the second covers special tonight behavior, the third lists entry contents, and the fourth explains detailed mode. Every sentence contributes distinct information with no filler.

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 read-only listing tool with complete schema coverage, an output schema, and safety annotations, the description covers all necessary calling context: what results look like, special behavior windows, entry fields, detailed mode, and general use guidance. Nothing essential is 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 coverage is 100%, so the baseline is 3, but the description goes beyond the schema by explaining what detailed mode includes (confidence level, source tier, reporting sources, verified_at timestamp) and clarifying the content and behavior associated with the 'when' parameter. This adds real semantic value beyond the input schema.

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 that the tool returns a ranked list of films playing in San Francisco theaters within a given window, with genre and format filters. It is specific about verb, resource, and scope, but it does not explicitly distinguish itself from siblings like scenef_search_showtimes or scenef_now, so differentiation is left to inference.

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 gives clear context for when to use the tool, including the supported windows (tonight, tomorrow, weekend, or a date) and the special 'Notable tonight' behavior. It even instructs the agent to lead with scarcity facts when asked what to see, but it does not mention when NOT to use this tool or name alternative sibling tools.

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