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

Beyond annotations (readOnly=false, idempotent=true, etc.), the description adds valuable behavioral details: links are permanent and free, each title plays as a full trailer, and it returns per-title resolution with an echo to catch mix-ups. This discloses expected side effects and output behavior, significantly aiding an agent's understanding.

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 four sentences, each with a distinct purpose: action/output, user experience, key properties (permanent/free), and usage guidance. There is no filler or redundancy, making it compact and easily skimmable.

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?

With no output schema, the description compensates by clearly stating what the tool returns (per-title resolution and playability). It also covers the main workflow (create, share) and appropriate use cases, making it complete for a tool with simple parameters and a single sibling.

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% with detailed descriptions for all parameters (items, title, language), so the baseline is 3. The description does not introduce new parameter-specific syntax but does hint at the 'items' parameter's role by discussing per-title resolution and playability, which indirectly supports understanding.

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 converts movie/TV recommendations into a playable trailer page on zinema.tv and shares the link. It uses a specific verb ('Turn... into') and identifies the resource and output, distinguishing it from the sibling get_list which retrieves existing lists.

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 explicitly says to use it 'whenever you recommend movies or shows' and explains the benefit over a text list ('a page that PLAYS beats a text list'). It does not explicitly name get_list as an alternative, but the context implies creation versus retrieval, providing clear functional guidance.

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