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

Annotations already declare mutation/idempotency safety, and the description adds genuinely new behavioral context beyond them: the kind-mismatch refusal semantics, the server-side app-access prerequisite, the account connection requirement, and the exact nature and 72-byte limit of the visitor password. This is rich disclosure for a mutation tool.

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?

Two tight paragraphs with the mode semantics front-loaded and edge cases second. Slightly repetitive against the schema's own mode descriptions, but no sentence is truly wasted.

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?

There is no output schema and annotations only cover the safety profile, yet the description fully equips the agent: what each mode does, the enum meanings, the kind-refusal rule, the app restriction, auth prerequisite, and password constraints. Nothing needed for a correct call 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?

Schema description coverage is 100%, so the baseline is 3. The description adds some semantics the schema doesn't fully carry (visitor password is not a Valet credential, is handed to viewers, 72-byte cap), but much of its mode/password prose duplicates what the schema already states.

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 and resource ('Set who can reach a website or app') and enumerates the three access modes it controls, so the agent immediately knows the domain. However, it never differentiates itself by name from adjacent siblings like share_site or publish_site, leaving that distinction to inference.

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 clear conditional guidance: the meaning of each mode, that kind should be passed to make mismatched names refuse rather than change, that apps require app access enabled on the server, and that a Valet account is required. It stops short of naming alternative tools (e.g. share_site) for cases the agent might confuse with this one.

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