host_capability_preflight

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

With no annotations, the description fully discloses behavior: it only performs filesystem stat, never executes, never probes arbitrary binaries, is not web/SOTA research, and does not verify auth. This is comprehensive and honest.

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 description is succinct (about 50 words), front-loaded with the main purpose, and every sentence adds necessary context (scope, safety, caveat). No redundancy.

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 preflight check tool with one optional parameter and no output schema, the description covers all needed aspects: purpose, method, limitations, and caveats. It is fully complete.

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% for the single parameter (runId), described as optional and for journaling. The description adds no extra parameter information, so 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?

The description clearly states the tool reports which known frontier-agent CLIs are installed on PATH. It uses specific verbs ('Local capability report') and resources, and distinguishes from siblings by focusing on static path checking.

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 gives implicit usage context (preflight check before using CLIs) and important caveats ('NEVER executes a command', 'Presence on PATH is not proof of working auth'). However, it does not explicitly contrast with sibling tools or provide alternatives.

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