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

Annotations only cover the safety profile (not read-only, open-world, non-destructive). The description adds genuinely new behavior: an approximate ~45s blocking wait, the fact that the agent works on a working copy, the four response shapes, and the polling fallback when the turn is unfinished. That is well beyond what annotations provide.

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 tight sentences, front-loaded with the primary action and timeout, followed by the outcome-to-next-step mapping. Every clause carries information; no filler.

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?

There is no output schema, so the description carries the return-value burden and does so by enumerating the four response types. Combined with the timeout and polling guidance, an agent has everything needed to invoke and follow up correctly.

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 chat_id, message, attachments, and plan_approved are already documented in the schema. The description reinforces plan_approved's role in the plan workflow but adds no format/syntax detail beyond the schema, so the baseline 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?

States a specific verb+resource (send a message to the Studio agent) plus the defining behavior (waits up to ~45s for the answer). It also names the sibling tools involved in the follow-up workflow (apply_turn, get_turn), so an agent can distinguish it from interject_turn/retry_turn without opening schemas.

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?

Enumerates the four possible outcomes and the exact next action for each: proposal -> apply_turn, priced plan -> reply with plan_approved:true, and still-working -> poll get_turn. This is explicit when/next-step routing rather than implied usage.

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