Show Playback Customizations

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

Annotations already cover readOnly/idempotent/destructive semantics, so the bar is lower. The description adds genuine context beyond them: the exact permission scopes required (including the delegate_to_contact token nuance) and the 'explicitly-set' vs default distinction, which is behaviorally important for interpreting the result.

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 informative purpose sentence is front-loaded and dense but earns its place by enumerating returned fields. The permission block that follows is boilerplate-heavy and long, though clearly structured and separated so an agent can skip it. Slightly verbose overall but not wasteful.

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?

There is no output schema, so enumerating the returned field groups is valuable and present. Combined with the explicitly documented auth requirements and the read-only annotation profile, an agent has everything needed to call and interpret this getter 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?

Schema description coverage is 100%, so both parameters (account, media_id) are already fully documented in the schema. The description adds nothing beyond 'for the video', which merely restates media_id. Baseline 3 is appropriate when the schema carries the load.

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?

States a specific verb ('Fetches') and resource ('playback customizations') and enumerates the exact field group (autoplay, mute, controls visibility, end behavior, etc.). The 'playback' specificity clearly distinguishes it from siblings like get_appearance_customizations or get_sharing_customizations without needing to open either schema.

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?

Usage is only implied: 'explicitly-set' hints that it returns only overrides rather than defaults, and it names the required permission. But it never states when to prefer this over get_customizations or the sibling customization getters, nor any when-not condition. Adequate but leaves routing to inference.

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