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

Annotations only say readOnly/openWorld=false; the description adds the operationally critical behavior: 'launching' for 5-6.5 minutes is expected due to Cloud Run IAM propagation, a ~30s polling cadence, probing the url once it appears, and a ~10 minute threshold for real failure. This is exactly the timing/semantics context annotations cannot convey.

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?

Front-loaded with the action and the handoff, then the timing guidance. Nearly every sentence earns its place, though the trailing '(see the anti-loop rules)' is a dangling pointer to external content that weakens the close.

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?

No output schema exists, and the description covers the key return signals (elapsed_s, 'launching' status, unreachable url). It stops short of describing the terminal success/failure states or the response shape beyond elapsed_s, which an agent would want before deciding to stop polling.

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%, so both parameters are already documented, including poll_url's provenance and the auto-detected default for `permanent`. The description restates the poll_url origin but never mentions the `permanent` flag or the expiry behavior it controls, so it adds little beyond the schema.

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 ('Poll a cloud deploy') plus explicit upstream dependencies (build_deploy or build_go_live) and the poll_url handoff. An agent can distinguish this from build_deploy/build_go_live/build_logs without opening any schema.

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?

States exactly when to call it (after build_deploy or build_go_live, passing the returned poll_url), how often to poll (~30s), and when to stop worrying vs. when it is a genuine failure (persistent unreachable past ~10 minutes). Effectively includes when-not-to-declare-failure guidance.

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