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

No annotations (e.g., readOnlyHint) are present, so the description carries the burden. It discloses a notable side effect: 'Re-saving preserves its note,' which informs the user about idempotent behavior. It also mentions privacy, adding context beyond the schema.

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, clearly stating the core action and an important behavioral nuance. No redundant or extraneous information is included.

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 sibling tools, the description sufficiently conveys the tool's role as an add operation. It does not mention output or required parameters, but those are covered by the schema and absence of an output schema. Overall, it provides enough context for correct usage.

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 parameter schema includes descriptions for all four parameters, and the description does not add significant additional meaning. It mentions 'article, video, blog post or link' which aligns with 'ref' and 'url', but no deeper semantics are provided. Baseline 3 is appropriate due to high schema coverage.

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 action (save) and resource (bookmarks for articles, videos, blog posts, or links). It does not explicitly distinguish from sibling bookmark operations (e.g., bookmarks_get, bookmarks_list), but the phrase 'privately' and 'Re-saving preserves its note' hint at its unique purpose of adding new bookmarks.

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 (saving new bookmarks) but does not explicitly state when to use this tool over alternatives like bookmarks_annotate or bookmarks_list. No direct comparison or conditional guidance is provided.

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