HTB Session Health Check

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds value beyond them by disclosing a prerequisite (HTB_API_KEY via env var or toolkit/.env.local) and failure semantics (errors only when the key or API check fails), though it does not describe the return shape.

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 tight sentences: purpose first, then when to run it, then the prerequisite. Every sentence earns its place with no filler, though the parenthetical about key origin adds slight density.

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 zero-parameter diagnostic with no output schema, the description covers what is checked, when to run it, prerequisites, and failure conditions. An agent has everything needed to call it correctly; only the exact response format is left implicit, which is minor.

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 the baseline is 4. There is nothing for the description to compensate for, and it correctly implies a no-argument invocation.

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?

The description states a specific verb (health check / verifies) and enumerates exactly what is checked: API key resolution and source, API connectivity via whoami, active machine, and VPN assignment. This clearly distinguishes it from action-oriented siblings like htb_machine_start or htb_vpn_status, which each cover a single concern.

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?

"Run this first in any session" gives explicit, actionable timing guidance that no sibling provides. There is no when-not-to-use or alternative named, but no sibling competes for the same diagnostic role, so the guidance is nearly complete.

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