Ping host

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

Annotations already provide readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false. Description adds useful behavioral detail: uses ICMP ping when available, falls back to TCP connect (works without root). No mention of timeouts or limits, but sufficiently covers key behavior beyond annotations.

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?

Three concise sentences with no waste. Front-loaded with main purpose, then key constraints and alternatives. Every sentence adds value.

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 tool with two parameters, no output schema, and strong annotations, the description fully covers purpose, usage, exclusions, and fallback behavior. No missing guidance.

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% with clear descriptions for host and tcp_port. Description reinforces that tcp_port is for fallback and default 443, but adds little beyond schema. Baseline 3 is appropriate.

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 'Reachability check' as clear verb+resource. Distinguishes from sibling tools by explicitly noting it does NOT check application ports or HTTP, and names alternatives (tcp_port_check, net_diagnose).

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?

Explicitly says 'Use this when you ONLY need to know if a host is alive' and provides exclusions: 'It does NOT check application ports or HTTP — for that use tcp_port_check or net_diagnose.'

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