mailbox_send

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

All annotations are false, so the description carries the burden of behavioral disclosure. It adds useful context by stating the message must be 'bounded UTF-8', but it does not explain what the bound is, side effects on the inbox, or failure modes. Some behavioral context is present, but significant gaps remain.

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?

The description is a single seven-word sentence with no wasted words. The core action, target, and constraint are all front-loaded, and every word contributes meaning. Appropriate for a simple two-parameter tool.

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 no output schema, the description covers the essential operation and encoding constraint, but leaves 'bounded' undefined and provides no information about error conditions or acceptable inbox values. The sibling mailbox_receive is not referenced, so the description is insufficient to fully contextualize behavior.

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?

With 0% schema description coverage, the description must compensate. It indirectly clarifies that 'data' is the UTF-8 message content (and is bounded) and that 'inbox' is the mailbox destination. However, it does not directly map parameters, explain the integer inbox range, or define the bound size, leaving ambiguity.

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 'Send' with a clear resource 'NXT mailbox message' and adds a meaningful constraint 'bounded UTF-8'. It clearly distinguishes itself from the sibling tool mailbox_receive, which performs the opposite operation.

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 provides no explicit guidance on when to use this tool versus alternatives. Although mailbox_receive is present in the sibling list, the description never mentions it or any circumstances that would select one over the other. Usage is only implied by the verb 'Send'.

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