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

The description says 'once' and 'Nobody is written to twice by this tool,' adding concrete no-duplicate behavior beyond the idempotentHint. It also reveals that the tool creates emails and drafts rather than merely returning links, which is useful behavioral context beyond the annotations.

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 only two sentences and has no filler, but the first sentence is a long run-on with 'for the family group and for anyone with no address' tacked onto the end, which is easy to misparse. The second sentence about no duplicate writes earns its place.

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 only two parameters, the description covers the main behavior well, but there is no output schema and the description only says the tool 'hands back a tap' without describing the shape of that tap or how the agent should surface it. That leaves a meaningful gap for an agent deciding what to return to the user.

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?

Both parameters are fully described in the schema, so the description does not need to add much. It aligns with the also_email parameter's send-vs-taps-only behavior but provides no additional semantic detail beyond what the schema already gives.

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 opens with a specific action—'Emails the invitation once to every person added with an address'—and names the two outcomes: invitation emails and a generated tap for drafts. This clearly distinguishes it from sibling tools like get_links or their_own_link, which focus on link retrieval.

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 this is the send step in the invitation flow and covers the family-group/no-address case, but it never explicitly states when to prefer this tool over siblings or when not to use it. The send-vs-taps-only decision is handled by the also_email parameter description rather than the tool description itself.

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