Preview service execution

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

The readOnlyHint annotation already signals a non-mutating operation. The description adds valuable context by stating 'without starting it' and clarifying that it produces an explanation of what would run, which is consistent with the annotation and provides a dry-run behavioral trait.

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 sentences long, front-loaded with the primary action, and every word contributes meaning. The second sentence immediately adds practical usage guidance without 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?

Despite having 7 parameters, nested objects, and no output schema, the description only covers the tool's purpose and a single hint about intents. It does not describe what the 'execution plan' contains, what inputs affect the plan, or any prerequisites, leaving significant gaps for an agent to invoke it 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?

With 0% schema coverage, the description needed to explain the parameters. It only indirectly hints at the 'intent' parameter by listing the enum values (start_dev/start_normal/debug_launch), but it does not explain language, project_root, cwd, env, config, or artifact_dir. This is insufficient given the schema provides no descriptions.

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 ('preview') and resource ('execution plan for a language service intent'), clearly distinguishing this from sibling tools that preview configs or operations. It explicitly mentions the related intents (start_dev/start_normal/debug_launch), which further clarifies its scope.

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 second sentence ('Use this to explain what...') gives clear context for when to use this tool instead of actually starting a service. However, it does not contrast with similar preview tools like preview_operation or suggest_service_runtime, so it lacks explicit exclusions.

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