list_sync_playback_movies

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds useful context about pagination behavior (defaults, maximums, clamping) and date formatting requirements, which goes beyond the schema. However, it doesn't disclose what the response contains or whether the endpoint requires authentication, though the output schema exists to cover return values.

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 front-loaded with the core purpose and endpoint, and the parameter list is organized. However, it is verbose: the 'watchnow' parameter explanation is a long block of repetitive text that could be condensed, and the 'Query parameter' placeholders for nine parameters add bulk without value. It earns a middle score for being structured but not tightly written.

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 tool has 15 optional parameters, an output schema, and annotations covering safety, the description covers the essential purpose and some parameter semantics. But it leaves significant gaps: no guidance on how to combine filters, no explanation of what 'extended' actually returns, and no mention of authentication requirements. For a complex list endpoint, this is adequate but not complete.

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 description coverage is 0%, so the description must compensate. It does add meaning for several parameters: 'extended' is explained with a list of valid values, 'watchnow' has detailed value explanations, and 'start_at'/'end_at' have format requirements. However, many parameters (genres, subgenres, years, ratings, start_date, end_date, runtimes, countries, certifications) are only labeled 'Query parameter' with no additional semantics, leaving the agent to guess their format or allowed values.

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 opens with 'Get movie playback progress' and includes the endpoint 'GET /sync/playback/movies', which clearly identifies the resource and action. It distinguishes itself from siblings like list_sync_collection_movies and get_sync_playback_by_type by focusing specifically on movie playback progress, though it doesn't explicitly name a sibling alternative.

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 the endpoint and parameter usage details, implying when to use it (to retrieve movie playback progress). However, it does not explicitly state when to use this tool versus alternatives like get_sync_playback_by_type or list_sync_progress_watched, nor does it mention any exclusions or prerequisites.

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