Update Customizations

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

Annotations already flag destructiveHint=true and idempotentHint=false, but the description adds crucial behavior beyond them: passing null DELETES a key from saved customizations (a non-obvious data-destroying rule), a confirm=true requirement, specific token permission scopes including delegation, and side effects ('share access, notify people or incur provider charges'). This is rich, high-value disclosure that goes well past 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 core behavior (partial update plus the null-deletes rule) is front-loaded in the first sentences, and the permission block that follows is dense but operationally necessary. Nothing is obviously wasted, though the permission prose is somewhat verbose.

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 43-parameter destructive mutation tool with nested objects and no output schema, the description covers the critical behaviors: the null-delete rule, required permissions, and the confirm requirement. It does not address the mutually exclusive body-flag vs payload/payload_file input modes (left to the schema), so it is slightly short of fully 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 coverage is 95%, so the per-parameter documentation is already in the schema (baseline 3). The description adds cross-cutting semantics the schema does not encode: null deletes a key while a non-null value sets it, which governs how every one of the 43 parameters behaves. That is meaningful added meaning over the schema.

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 states a specific verb and resource ('partial updates on a video's customizations'), so an agent knows exactly what operation is performed. However, it never distinguishes this general tool from the many granular siblings (update_appearance_customizations, update_playback_customizations, update_chapters_customizations, etc.), leaving the agent to guess which one to call.

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?

There is no when-to-use vs alternative guidance despite ~15 sibling customization updaters in the set. The null-semantics rule hints at how the call behaves, but the description never says when to prefer this general tool over the category-specific update_*_customizations tools, nor does it name any alternative.

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