machines_list

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

Annotations already mark the tool read-only and non-destructive. The description adds a behavioral guarantee beyond those hints: it never contacts remote machines, which has latency and side-effect implications. This is useful additional transparency, though it does not describe output shape or edge cases.

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 short sentences, front-loaded with the action, then two clarifying facts. Every sentence earns its place and there is no filler or repetition of annotation content.

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, read-only list tool without an output schema, the description is complete: it states what is returned (registered remote machines), that no remote contact is made, and what selectors apply to the machines. No critical context appears missing.

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 input schema defines zero parameters, so the baseline for this dimension is 4; there is no undocumented parameter burden. The mention of selectors (id, name, hostname, alias, IP, host:port) is identity/context information rather than parameter documentation, but it still adds helpful meaning beyond the empty schema.

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?

Opens with a specific verb and resource: 'List registered remote machines.' The final sentence clarifies the operation is local-only ('does not contact remote machines'), which distinguishes it from interacting or probing tools like machine_status or machine_probe. The selector list adds context without blurring the core purpose.

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 'does not contact remote machines' statement gives a clear, safe-use context: use this when you need the registry of machines without triggering network activity. It does not explicitly name alternatives or exclusion cases, so it falls short of a 5, but the usage context is clear.

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