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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds useful context by stating that visitors will need the password to view the site, but it does not disclose whether an existing password will be overwritten or whether any site-owner permissions are required.

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 tight sentences with no filler. It front-loads the core action and immediately supplies the key constraint and the visitor-facing consequence.

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?

For a simple two-parameter mutation, the description captures the essential action, the paid-plans restriction, and the resulting behavior, with annotations covering idempotency and non-destructiveness. It misses only minor context like overwrite behavior or a pointer to the inverse sibling tool, so it is nearly complete.

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?

With 0% schema description coverage, the description must compensate, and it only partially does so: 'site' maps to siteId and 'password' is implied as the credential visitors will need. It does not explain value formats, length rules beyond the schema's minLength, or how siteId should be determined.

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 leads with a specific actionable phrase, 'Password-protect a site,' clearly naming the resource and the intended effect on visitors. The paid-plans qualifier and the visitor-password explanation further distinguish it from sibling tools like remove_site_password.

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 identifies the main scenario and a clear eligibility condition: use it to password-protect a site, and only on paid plans. It does not explicitly mention alternatives such as remove_site_password for the reverse operation, so it does not fully route the agent away from related tools.

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