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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses real behavior: sites are located wherever the panel keeps them, also derived from the web server's own configuration, and inside Docker containers when files are mounted from the host. It also carries a useful security guarantee ('passwords are never shown') and notes metadata is read from each site's own configuration. It stops short of stating auth requirements or cost/latency on hosts with many sites.

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 resource is front-loaded but the body is one very long run-on sentence that chains stack names, discovery mechanisms, and a long trailing list of returned fields. The content is substantive rather than filler, yet the nesting hurts scannability.

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 output schema, the description takes on the job of describing the response and does enumerate the per-site fields (kind, root, docroot, domains, logs, owner, version, DB name and prefix, CLI tool, WooCommerce version, container). What is missing is behavior when multiple servers exist and any note on result size or pagination.

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?

There is a single optional `server` parameter with 100% schema description coverage, so the schema already explains that it accepts a name or id and is optional on single-server accounts. The description adds no syntax, default, or multi-server behavior beyond that, so the baseline 3 applies.

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?

Names the resource ('the sites on the server') and enumerates the supported stacks (Magento, WordPress/WooCommerce, PrestaShop, Shopware, Drupal, Joomla, OpenCart, Laravel, Ghost) plus the discovery sources, so an agent knows exactly what is retrieved. It never names or contrasts a sibling such as list_servers or connected_sites, which is the only thing keeping it from a 5.

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?

Usage is only implied: an agent infers this is the way to inventory sites hosted on a server, and the mention that a site's console is 'run with site_console' routes one follow-up action. There is no explicit when-to-use statement, no exclusion of alternatives, and no stated prerequisite or permission requirement.

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