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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: results are limited to sites the account can manage, and custom-domain sites expose a preview URL that works before DNS is configured. Missing only auth/rate-limit or result-limit details.

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 describing contents followed by a two-word directive, with the enumeration and the "call this first" instruction both front-loaded. No filler and no repetition of the title.

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?

An output schema exists and annotations cover the safety profile, yet the description still adds value by summarizing what each site record contains and framing the tool as the entry point. For a no-parameter listing tool, nothing an agent needs to invoke it correctly is missing.

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; the baseline for a parameterless schema is 4. The description appropriately avoids inventing filtering options that do not exist.

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 (Lists) and a scoped resource (websites this account can manage), then enumerates the returned attributes (plan type, status, SSL, DNS editability, preview URL). This makes it clearly a multi-site enumeration tool, distinguishable from singular siblings like get_site_info and check_site.

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?

"Call this first." gives an explicit, actionable ordering directive that tells the agent when to reach for this tool relative to the rest of the workflow. It does not name alternatives or state exclusions, but the sequencing guidance is concrete rather than implied.

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