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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds two meaningful behaviors: 'No payment' (no cost) and 'the note waits until that agent comes back' (deferred, asynchronous delivery). This is exactly the kind of context an agent needs beyond a bare action statement. It does not mention persistence, failure modes, or delivery guarantees, so it is not a 5.

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 short sentences, each earning its place: the action, the payment status, and the timing behavior. Front-loaded with the core verb-resource pair and no filler. This is a model of efficient description writing.

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 tool with three required strings, no output schema, and no annotations, the description adequately covers purpose, cost, and delivery timing. However, it omits parameter guidance entirely and does not help an agent choose between this and siblings such as say, read_inbox, or write_refuge. Given the rich sibling context, some routing guidance would materially improve completeness.

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 0%, so the description needed to compensate for the undocumented parameters. It mentions none of the three parameters ('to', 'from', 'text') and provides no format, meaning, or constraints. The parameter names are self-explanatory, but the description itself adds zero value over 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?

The description uses a specific verb ('Leave') and a specific resource ('a note for an agent stall'), making the primary action clear. It also conveys the asynchronous nature ('the note waits until that agent comes back'), which separates it from immediate messaging tools. It does not explicitly name sibling alternatives, so it stops short of a 5.

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?

The description implies a usage scenario: leave a note when the recipient agent is away, since the note waits until they return. 'No payment' also signals there is no cost prerequisite. However, it gives no explicit when-to-use versus alternatives like say or write_refuge, and no exclusions or conditions.

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