Start the simulation

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

Annotations cover only the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), and the description adds genuinely useful behavior: it is synchronous, returns as soon as the run is up, and fails fast with Simulink's own error text if compilation fails. It stops short of disclosing the file-writing side effect of the default save mode, which matters for a non-read-only tool.

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, zero padding, with the primary action, its failure mode, and the next step ordered by importance. Nothing could be cut without losing 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?

With an output schema present and full parameter documentation, the description only needs to explain the call's lifecycle, and it does: start, fail-fast on compile error, then poll with cm_wait_end. Nothing an agent needs to invoke it correctly is missing.

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 100%, so the schema already documents save/collect/keep, save_logs, and start_timeout_s in detail. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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?

Specific verb + resource ('Start the loaded test run') with the scope qualifier 'loaded' that separates it from cm_load_testrun. An agent can distinguish it from cm_stop_sim and cm_wait_end purely from this sentence.

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 sequences the workflow by naming cm_wait_end as the required follow-up call until it reports finished, which is real routing guidance. It does not state the prerequisite explicitly (that a test run must already be loaded) or when NOT to call it, so it falls short of a 5.

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