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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's addition of listing returned fields provides context but is not critical. No behavioral quirks are disclosed beyond what annotations convey.

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 efficient, uses bullet-style examples for readability, and is front-loaded with the primary purpose. Slightly verbose in listing all fields, but overall concise.

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 simple tool (1 param, no output schema, clear annotations), the description is complete: it explains what the tool returns and when to use it, leaving no major gaps.

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% and the single parameter is well-described. The description adds no further details or examples for the parameter, so it carries its baseline value without extra benefit.

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 provides a complete movie card with specific fields (synopsis, cast, direction, genres, etc.). It distinguishes from siblings by explicitly naming alternatives for showtimes and general listings.

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 includes concrete usage examples (e.g., 'de qué va Oppenheimer', 'quién sale en esa película') and explicitly states when not to use it, naming the appropriate sibling tools (find_movie_showtimes, get_cartelera_localidad).

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