Create bookmark

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

With no annotations, the description carries the full burden for behavioral disclosure. It reveals that a second bookmark at the same second is rejected, which is critical for understanding idempotency. However, it does not describe the return value or any side effects beyond creation, which is a minor gap.

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 two concise sentences, the first declaring purpose and the second adding a critical constraint. Every sentence earns its place with no redundancy.

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 absence of an output schema, the description is mostly complete for a simple create operation. It covers the core behavior, but omits mention of the return value and validation of library_item_id, which would help an agent anticipate the response.

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 already covers all parameters (100% coverage), so baseline is 3. The description adds meaningful context for the 'time' parameter by stating it is the bookmark's identity and that duplicates are rejected, which exceeds the schema description.

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 creates a bookmark with specific details (at a position, for the API key's user), distinguishing it from siblings like list_bookmarks, update_bookmark, and delete_bookmark.

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?

No guidance is given on when to use this tool over alternatives, no prerequisites or exclusions are mentioned, and the rejection condition (duplicate time) is a constraint rather than a usage guideline.

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