x_bookmark_set

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

Beyond the annotations, the description explains that bookmarks are private, that the operation is reversible, that it reports the resulting bookmarked state, and that it is disabled by policy read-only. This adds meaningful behavioral context without contradicting the idempotent or non-destructive hints.

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 compact and front-loaded with the core purpose. Subsequent sentences add relevant privacy, input format, result behavior, and policy context without any filler or repetition.

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?

With an output schema present, the description does not need to detail return structure. It covers the operation's effect, input format, privacy implications, reversibility, result reporting, and policy restriction, making it fully adequate for correct invocation.

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 schema already documents both parameters and their formats at 100% coverage, including the enum and URL example. The description restates the accepted post format and action values, which is helpful but does not add meaningful new semantics beyond the schema.

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: add or remove a bookmark for the authenticated user, naming the specific resource (bookmarks) and distinguishing it from list and other engagement tools. The phrase 'add a post to the authenticated user's bookmarks or remove it' is a specific verb+resource combination.

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 makes the tool's context clear: it is for mutating bookmark state, and the read-only policy note indicates when it might be unavailable. It does not explicitly name alternatives like x_bookmarks_list or x_like_set, but the domain is unambiguous enough that an agent can select it appropriately.

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