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

With no annotations, the description carries the full burden and mostly delivers: it explains the 10-minute cookie rotation, the resulting 401/empty-list symptoms, and that all other tools retry this automatically. It stops short of describing what a failed refresh looks like versus a transient error, or any cost/latency of the in-place refresh.

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 its key constraint, and the diagnostic/alternative guidance is packed efficiently. The middle clause about cookie rotation is dense and slightly run-on, but no sentence is wasted.

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 zero-required-param, no-output-schema tool with no annotations, the description covers purpose, trigger conditions, failure modes and the fallback path. It only omits what a successful versus failed refresh returns, which an agent calling it deliberately would want to know.

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?

Only one optional parameter and schema coverage is 100%, so the schema already fully documents notification_message; the description adds nothing about it. Baseline 3 applies since the schema does the work.

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 and resource ('Refresh the saved Play Console session in place') and immediately narrows the semantics with 'no new browser sign-in', distinguishing it from start_browser_auth. An agent can tell what it does and what it is not without opening the 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?

Gives explicit when-to-use conditions ('before a long sequence', 'to tell a stale cookie apart from a session that has genuinely ended') and an explicit exclusion ('Every tool already retries this automatically on a 401'). It also names the only alternative when this fails: start_browser_auth.

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