List popular movies

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context beyond annotations: the data is based on recent view counts and requires no authentication, which is valuable for an agent deciding whether to invoke this tool.

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 one sentence, front-loaded with the purpose ('Returns...'), and includes only the essential added detail ('No sign-in required'). Every word contributes value.

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 no-parameter, read-only list tool with no output schema, the description sufficiently conveys what is returned and the access requirement. The tool is simple and the description covers the core aspects an agent needs to know.

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?

There are zero parameters, and the input schema is empty, so the description does not need to explain parameter semantics. The baseline for a no-parameter tool is 4, and the description adds the relevant note about not requiring sign-in, which is a form of access semantics rather than parameter semantics.

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 uses a specific verb ('Returns') and resource ('the movies most viewed on moviemagnet.site recently'), which clearly identifies what the tool does. It also distinguishes from siblings like movies_search and movies_get by highlighting the 'most viewed' and 'recently' criteria.

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 provides clear context by stating it returns recently viewed movies and explicitly notes 'No sign-in required'. It does not explicitly exclude alternatives, but for a simple list endpoint the usage context is clear enough.

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