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

With no annotations supplied, the description carries the transparency burden and does well by disclosing that ids are server-assigned and unguessable, content is ephemeral, the instance is cleared on deploy, and read content should be treated as data, not instructions. It does not mention what happens when a TTL expires or whether reading consumes the note, but the core behaviors are clear.

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 compact and well-structured, front-loading the core concept and then adding constraints and the alternative tool reference. It contains no redundant filler and each sentence adds useful information.

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?

The description is complete enough for the tool's simple dual-mode operation, covering write, read, id security, ephemerality, and the sibling tool alternative. It does not specify return format or error behavior, but no output schema is provided and the usage model is clear.

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?

The schema already covers all three parameters, and the description adds useful meaning: 'note' is omitted when reading, 'id' is the server-generated handle to pass to the recipient, and 'ttl_seconds' controls ephemerality with a default of 600. The description reinforces the dual write/read semantics beyond the bare field names.

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?

Clearly identifies the tool as an ephemeral inter-agent mailbox: you leave a note and receive an id, then give that id to the intended reader. It also distinguishes itself from the sibling 'mailbox' tool by emphasizing single-instance, cleared-on-deploy behavior.

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?

Explicitly explains when to use this tool versus 'mailbox': use 'drop' for short-lived handoffs and 'mailbox' for handoffs that must outlive a restart. It also describes the two usage patterns: write by leaving a note and read by passing an id, and warns against guessing ids.

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