check_connection

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

Annotations already indicate readOnly=true, idempotent=true, destructive=false. The description adds meaningful behavioral context beyond annotations: it distinguishes 'Darwin is not running' from 'Darwin refused the command', explains the darwin.state and darwin.hint output fields, and notes that the account need not be logged in. This enriches the agent's understanding of what the tool does at runtime.

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 concise and well-structured, with each sentence contributing unique value: purpose, when to call, and what output to expect. It avoids redundancy and is front-loaded with the core purpose.

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?

Given the tool's simplicity (no params, clear annotations, output schema present), the description is complete. It covers purpose, usage context, behavioral nuances, and state output, leaving no significant gaps for an agent to misuse or misunderstand the tool.

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 has zero parameters, so the schema covers everything. The description adds context about what the tool checks (ports reachability) and the state/hint outputs, but since there are no parameters, the baseline of 4 is appropriate. No further param documentation is needed.

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's function: 'Check whether Darwin's local trading and historical-data ports are reachable.' It uses a specific verb ('check') and resource ('Darwin's ports'), and distinguishes it from siblings by positioning it as the first tool to call when other tools fail, separating connection issues from command failures.

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?

Explicit usage guidance is provided: 'Call this first if any other tool fails' and 'This is also the tool to poll after start_darwin, once the user says they have finished the login.' It clarifies prerequisites (Darwin running and listening, not logged in) and differentiates this tool from alternatives like get_darwin_status.

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