trace_start

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

No annotations are provided, so the description must disclose behavior. It describes that it configures and starts the MCDS trace engine, mentions parameters and their defaults, and returns a confirmation. However, it does not mention any side effects, state changes, or constraints beyond the sequence, such as whether it can be called multiple times.

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 front-loaded with the purpose, followed by usage instructions, parameter details, and return value. It is well-structured, concise, and contains no unnecessary information.

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 presence of an output schema and the detailed parameter explanations, the description covers all necessary information for tool invocation. It also differentiates from many sibling trace tools.

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 description includes an Args section that explains the purpose, allowed values, and defaults for both parameters (sources and timestamps). This adds significant meaning beyond the schema, which only provides type and default.

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 'Start on-chip trace recording using MCDS.' The verb 'start' and resource 'trace recording' are specific, and it distinguishes from sibling tools like trace_stop, trace_list, etc.

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?

Explicitly provides when to use: 'Must be called before running the target.' Also gives follow-up actions: 'Call trace_stop() and trace_list() after the target halts.' This offers clear usage context.

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