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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is low, and the description still adds the concrete payload contents — status values, last-check time, and uptime windows. That is meaningful context beyond structured fields, though it omits anything about ordering or response size.

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 compact sentence that front-loads scope and enumerates returned fields with no filler. The trailing 'Free' is slightly ambiguous but costs almost nothing.

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 parameters and no output schema, the description's job is largely to describe what comes back, and it does list the key fields. It stops short of covering pagination, sorting, or other attributes (URLs, response times), which leaves a small gap for a no-arg listing tool.

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 to disambiguate; baseline 4 applies. The description correctly implies a no-argument enumeration of all monitors.

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?

Effectively states the resource (every watched page/monitor) and the fields surfaced (status up/down/paused, last check, uptime 24h/30d), which distinguishes it from the single-monitor sibling uptime_get_monitor. The verb 'list' is implied rather than stated, but the scope is unmistakable.

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 phrase 'Every watched page' implies this is the list-all tool versus uptime_get_monitor for a single monitor, but it never names the alternative or states when to prefer it. Usage is inferable rather than guided.

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