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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine value by describing the returned content (reachability, per-region results, incidents — there is no output schema to carry this), but it does not say whether the check is live-triggered or read from stored history, nor anything about volume or retention.

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 front-loaded sentence with zero filler; the subject (uptime) leads and the three output facets follow. It could push slightly further by naming the sibling it complements, but nothing is 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?

With no output schema, the description carries the return-value burden and does so in compressed form — enough for an agent to know what it gets back. Combined with fully documented parameters and read-only annotations, an agent has what it needs to invoke this correctly.

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 schema already documents all five parameters including the from/to offset formats and the project/environment defaults. The description adds nothing about parameters, which is acceptable at this coverage level — baseline 3.

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 ("Show a Service's uptime") and enumerates the three things it surfaces: visitor reachability, per-region check results, and incidents. It is clearly distinguishable from mutation siblings like service_restart, but it never differentiates itself from the close sibling uptime_check.

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 explains what the tool returns but gives no guidance on when to reach for it rather than uptime_check, service_status, or service_metrics. No prerequisites, no exclusions, no named alternative — the agent must infer the choice from the content list alone.

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