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

Annotations declare readOnlyHint=false, so the mutation nature is already known. The description adds context about the boolean semantics (true/false) and the 'private' nature of the preference, but does not disclose side effects like overwriting existing preferences or permission requirements. Given annotations, the additional context is moderate but not exhaustive.

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 with no wasted words. It front-loads the purpose and explains the key parameter semantics, making it efficient for an agent to parse.

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 that an output schema exists (though not shown), the description covers the necessary input semantics and the tool's purpose. It doesn't explain return values, but those are presumably in the output schema. For a simple set operation, the description is adequate.

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?

Schema coverage is 0%, so the description must compensate. It explains the 'following' parameter with the true/false semantics. The 'page_id' parameter is not explicitly described but is self-explanatory given the context of a follow preference on a page. This adds meaning beyond the bare 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 uses a specific verb ('Set') and resource ('follow preference') and explains the effect ('True follows future page changes; false stops following'). It clearly distinguishes from sibling tools like read_page or create_page by focusing on the follow preference action.

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 when to use the tool (when wanting to follow or unfollow a page) but does not explicitly state alternatives or exclusions. There is no mention of other tools to use instead, so guidance is only implied.

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