watchlist_activity

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

The annotations indicate readOnlyHint=true, and the description does not contradict that. It mentions ordering (newest first) and cost (Free), but does not detail side effects or output behavior. However, the read-only nature is adequately covered by 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 description is concise and well-structured, conveying the core functionality in two short sentences. It avoids unnecessary detail while remaining informative.

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?

The description provides enough context for a straightforward retrieval tool, including the pairing advice for question-answering. It does not describe output schema, but that is not required given the simplicity and the lack of output schema definition.

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 watchlistId parameter has a clear description referencing list_watchlists, which is helpful. The limit parameter lacks a description but is self-explanatory as a numeric limit, so semantics are sufficiently clear.

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 the tool's function: retrieving the most recent videos recorded for a specific watchlist, ordered newest first. It also distinguishes itself from siblings by specifying 'one watchlist' and including the pairing hint with search_transcript.

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 a usage hint by suggesting pairing with search_transcript, but does not explicitly state when to use this tool versus alternatives like list_channel_videos or get_transcript. It implies usage but lacks direct guidance on selection.

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