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

With no annotations, the description carries the full disclosure burden, and it does deliver real behavioral detail: each wake-up is returned only once (an at-most-once delivery guarantee), and results carry saved state plus thread ID. What is missing is the safety profile (read-only nature), any rate/pagination behavior, and what happens to due items after they are collected.

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 sentences with no filler. The core behavior (what is collected, what comes back) is front-loaded and the actionable instruction sits last, which is exactly the right ordering for an agent scanning for what to do.

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 no output schema and no annotations, the description correctly compensates by describing the returned payload (due items with saved state and thread ID, plus upcoming ones). It is close to complete for a single-optional-param read tool, with only minor gaps around ordering and whether collecting consumes the wake-ups.

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?

There is a single optional parameter and schema coverage is 100%, so the schema already explains the inbox name, its secrecy requirement, and the API-key alternative. The description adds nothing about the parameter, which is acceptable at the baseline when 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?

The description names a specific action and resource: it collects due wake-ups for the inbox and lists upcoming ones, and it discloses what each returned item contains (saved state, thread ID). That is unambiguous against the read-side counterpart of the sibling tools. It does not, however, explicitly name or contrast itself with schedule_wake or cancel_wake, so the differentiation is inferable rather than stated.

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?

"Call this at the start of a session" gives an explicit trigger condition, which is more than most definitions provide. It stops short of a 5 because it never states when not to call it, nor does it name the sibling alternatives (schedule_wake / cancel_wake) and the conditions that would route an agent to them instead.

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