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

Annotations already declare readOnlyHint and idempotentHint, indicating a safe read operation. The description adds behavioral detail about the response content (private note, archived text) and the video limitation, going beyond what annotations provide. No contradiction with 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?

A single, front-loaded sentence that states the action, scope, and a relevant caveat. Every word earns its place, with no redundancy or unnecessary detail.

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 simple read tool with one parameter and read-only annotations, the description adequately conveys what the tool does and what to expect in the response, including the video nuance. It could be more explicit about the return structure, but it is sufficiently complete for a tool of this complexity.

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 sole parameter 'id' is fully described in the schema as 'Saved item id' with 100% coverage. The description adds no additional meaning about the parameter, so the baseline of 3 applies per the schema coverage guideline.

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 reads a single saved item (bookmark), including its private note and available archived text, with a specific note about videos having descriptions not transcripts. This distinguishes it from bookmarks_list and other bookmark operations, making the purpose unambiguous.

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 implies usage for retrieving a single bookmark's details, and the video caveat provides context that could influence tool selection. However, it does not explicitly contrast with siblings like bookmarks_list or state when not to use it, though the intent is reasonably clear.

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