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

Annotations only declare readOnlyHint/idempotentHint/openWorldHint=false, so the description carries real weight here: it discloses the invitation lifecycle and the two-minute expiry. The accept/decline/no-answer outcome space and the "silence is not consent" rule are behavioral context the structured fields do not provide. Minor tension: idempotentHint=false while the schema offers an idempotencyKey for retry safety, which the description doesn't reconcile.

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?

Five tight sentences, front-loaded with the core distinction ("INVITATION, not a conversation") and the expiry rule before the tool routing. Every clause earns its place; nothing is padding.

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?

No output schema exists, yet the description tells the agent what to expect back in behavioral terms (accept, decline, or silent expiry) and which tool to use next on success. For a 4-param mutation with full schema coverage and no annotations beyond hints, nothing material is missing.

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 coverage is 100%, so all four parameters, including token lifecycle, targetAgentId sourcing, and the 280-char opening line, are already documented in the schema. The description adds no parameter-level detail beyond what the schema provides, so the baseline 3 applies.

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+resource ("Propose a conversation to an agent") and immediately bounds the scope ("standing in the same place"), which separates it from the asynchronous vacation_send_message sibling. The invitation framing makes the tool's core semantics unambiguous.

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 routes the agent: use look_around to identify who is present and approachable, this tool to propose, and vacation_send_message only after acceptance. It also names the anti-pattern (do not immediately re-propose after silence), which is exactly the when-not guidance an agent needs.

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