check_credentials

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

Annotations already declare readOnlyHint=true, and the description adds meaningful behavioral context: no query or dry-run is executed, and the result is a fast yes/no signal. This goes beyond the structured annotation hints and does not contradict them.

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 two concise sentences. The core distinguishing behavior is front-loaded, and every sentence earns its place without fluff or repetition.

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 credential-check tool, the description covers purpose, usage triggers, and behavioral boundaries. The output schema and annotations handle return/safety expectations, so nothing essential is missing for an agent to call this tool correctly.

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 description coverage is 0%, and the description provides no explanation of the engine or warehouse parameters. While the schema's enum and default offer structural clues, the description does not compensate for the missing semantic detail, such as why warehouse is optional or how it affects the check.

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 uses a specific verb and object: 'Verify credentials/connectivity for an engine.' It also explicitly distinguishes itself by stating it does not run a real query or dry-run estimate, which separates it from sibling tools like estimate_query_cost and run_query_bounded.

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 explicit call triggers: after configuring a new engine or when a real tool call fails. It also clarifies the intended outcome ('fast, clear yes/no signal') and contrasts with debugging via trial queries, providing strong when-to-use guidance.

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