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

Annotations already declare readOnly/idempotent/non-destructive, and the description still adds substantial behavior: data provenance and freshness ('Royally's hourly site health check'), the exact meaning of plugin types (must_use, dropin), null semantics for requires_php/requires_wp/tested_up_to, and the enumerated alert classes. This is far beyond what the annotations convey.

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 purpose is front-loaded, but the body is a single ~150-word sentence dense with stacked parentheticals that are hard to parse on first read. The content is mostly useful, yet it would earn its place better as short structured clauses rather than one run-on.

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 does the work of describing the returned fields and alerts, so an agent knows what comes back. The remaining gap is operational: a fleet-wide inventory over every monitored site says nothing about result size, pagination, or truncation behavior.

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 coverage is 100%, so baseline is 3, but the description adds genuine meaning: the plugin filter is case-insensitive and result-shaping ('returns only sites that have it, listing only the matches'), and php_below is clarified against the schema's 'branch is lower than this'. site_ids receives no extra narrative, but the schema already documents it fully.

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?

Opens with a specific verb+resource+scope: 'Platform and plugin inventory for every connected site', naming exactly what is returned (WP/PHP/DB versions, theme, disk, plugins, alerts). It is distinguishable from fleet-wide vs single-site siblings by the 'every connected site' scope, but it never names a sibling (e.g. fleet__list_plugins, fleet__health_summary) to sharpen the boundary.

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?

Ends with a concrete use case: 'Use this to answer which sites run a plugin or version before planning updates', and explains how the two filters narrow results. It gives clear when-to-use context but no explicit when-not-to-use or named alternative for single-site or plugin-detail lookups.

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