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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), and the description adds two genuinely new facts: it does not upload/create/read, and processing may consume compute and analysis resources. That resource-consumption warning is valuable and not in the structured data, but nothing is said about whether processing is async/long-running or how completion is signalled, so the disclosure stays modest.

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?

Two tight sentences with no filler, and the core action is front-loaded ahead of the caveats. Every clause earns its place.

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, return values need not be described, and the description covers the action, side-effect boundaries, and resource cost. The one remaining gap is the undocumented 'id' parameter, but for a one-parameter mutation tool the definition is otherwise sufficient.

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 single 'id' parameter has 0% schema description coverage, so the schema does not carry the burden. The description only hints that it refers to 'an existing ECU definition file'; it never states the identifier format or where the id comes from (e.g., list_ecu_files), so it fails to compensate for the coverage gap.

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?

States a specific verb ('Start or retry processing') and resource ('an existing ECU definition file'), and explicitly rules out upload/create/read, which helps an agent separate it from list_ecu_files and inspect_ecu_file. However, it does not resolve its near-overlap with the sibling retry_ecu_file, leaving ambiguity about which to pick.

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?

It implies the precondition that the file must already exist ('an existing ECU definition file') and rules out upload/create/read operations, which is useful negative guidance. But it never states when to use this versus the sibling retry_ecu_file or inspect_ecu_file, so the routing guidance is only implied.

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