Update Playlist

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

The description adds the important merge behavior (fetch current, merge fields) beyond annotations. Annotations already indicate it's not read-only, not destructive, not idempotent. The description provides additional context on error codes and preservation of omitted fields.

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 well-structured with clear sections (Args, Returns, Examples, Errors). It is concise, with no unnecessary words, and front-loads the main action.

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's complexity, the description covers behavior, parameters, examples, errors, and return format. No output schema exists, but the return description is sufficient.

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?

The input schema has 100% coverage, and the description adds value by explaining the preservation behavior for each optional parameter (e.g., 'Preserves existing if omitted'). This goes beyond the schema's descriptions.

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 'Update metadata of an existing playlist'. It uses specific verb+resource (update metadata) and distinguishes from sibling tools like create_playlist and delete_playlist.

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 explains the merge behavior and error conditions, and provides examples. However, it does not explicitly guide when to use this tool versus alternatives like youtube_update_playlist_item, but the context is clear for metadata updates.

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