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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds beyond that: 'costs no credits, and starts nothing. Requires an API key. Returns runs newest first with paging.' These are valuable behavioral details (pricing, side-effect confirmation, auth, ordering). Not quite a 5 because the core safety profile is already covered by annotations, but the extra context earns a solid 4.

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?

Four sentences, each with a distinct job: purpose, usage guidance, alternative tool, and behavioral details. No filler, all information is actionably relevant. Well-structured and front-loaded.

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 simple read-only list tool with no output schema, the description covers enough: what is returned (status and result summaries), ordering (newest first), paging, side effects (none), pricing (no credits), and auth requirement. It also correctly points to get_autopilot_status for single-run detail. This is complete for the tool's complexity.

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 coverage is 100%: both 'limit' and 'offset' have descriptions. The description adds no additional parameter-level meaning beyond what the schema provides. Baseline 3 is appropriate because the schema does the heavy lifting.

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?

Description opens with a specific verb-action ('List past and running autopilot runs with their status and result summaries'), clearly identifying the resource and scope. It also distinguishes itself from the sibling tool get_autopilot_status by noting that the latter provides detail on a single run.

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 states when to use: 'Use it to review what has already been run — and to check for a run already in flight before start_autopilot launches a second one.' It also names the alternative: 'For detail on one run, use get_autopilot_status.' This gives clear context and exclusions.

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