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

The description adds meaningful context beyond the readOnlyHint and openWorldHint annotations by explaining dynamic state transitions from 'pending' to 'playable' or 'no_trailer'. It confirms a read-only operation that reflects changing conditions without contradicting 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 two well-structured sentences: the first states the tool's purpose, the second explains the possible status transitions. It is front-loaded and contains no redundant or unnecessary words.

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 simple tool with one parameter and no output schema, the description provides sufficient context about what the tool does and the significance of the statuses. It could be more explicit about the exact return format, but the phrase 'which titles play now' and the status explanations give an agent enough understanding to invoke it correctly.

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 schema already fully documents the single parameter 'code' as the list code returned by create_list. The description does not add extra parameter details beyond a slight contextual reminder that the list was created earlier, so the baseline for high schema coverage is appropriate.

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 checks a previously created list and reports which titles currently play. It uses a specific verb ('check') and resource ('zinema list'), and it distinguishes itself from the sibling create_list by focusing on inspection rather than creation.

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 implies the tool should be used after create_list by referencing 'a list you created earlier'. It does not explicitly mention when not to use it or name alternatives, but the sibling relationship and wording make the intended usage clear.

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