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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful non-annotation behavior: each group is truncated to the first 10 with totals, and expiry times are shown for previews. It stops short of describing ordering or pagination cursor behavior, hence not a 5.

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 dense sentence, front-loaded with the tool's scope and grouping, followed immediately by the truncation constraint and the routing to alternatives. Every clause carries information; nothing is repeated from the title or schema.

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 no parameters and no output schema, the description must carry the full burden of describing the result, and it does: two groups, expiry times for previews, a hard 10-item cap per group, and totals. An agent knows exactly what it will get and when to go elsewhere.

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 tool takes zero parameters, so there is nothing for the description to disambiguate beyond stating the scope of what is listed. The two-group framing is the relevant semantic context and it is provided.

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?

States a specific verb (list/overview) and resource (published sites plus temporary previews), and explicitly partitions the output into two named groups. It differentiates itself from siblings by naming list_permanent_sites and list_previews as the narrower alternatives.

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?

Gives an explicit when-to-use (you want a combined overview) and when-not (you want a complete list of one kind, in which case use list_permanent_sites or list_previews). The alternative tools are named and the selecting condition is stated, leaving nothing to inference.

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