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

Annotations already signal write/destructive behavior, so the description earns credit for adding useful context: it restarts with fresh environment variables and fails with 'Container not found' when the server is not running. This goes beyond the schema and annotations without contradicting 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?

Three short sentences, each carrying distinct value: what the tool does, when to use it, and a known failure mode. No filler or 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 single-parameter restart tool, the description is complete: it explains the action, the fresh environment variable behavior, when to invoke it, and the expected failure mode when the server is absent. The output schema and annotations cover the remaining structured information.

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 schema already documents project_name with 100% coverage, so the description does not need to add parameter-level detail. The description adds no meaning beyond the schema, which is acceptable at the baseline.

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 action and resource: 'Restart a running preview server with fresh environment variables.' This clearly distinguishes it from siblings like start_dev_server and redeploy by specifying 'running' and 'preview server.'

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 explicitly says when to use it: 'after project secrets change, or when the preview is stuck.' It does not explicitly name alternatives or state when not to use it, but the failure condition implies that start_dev_server is the alternative if the server is not running.

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