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

With annotations providing no meaningful safety detail, the description fully carries the burden: it states the human forwards the invite themselves, the link contains the asker's first name and reason, confirmed joins contribute up to three flags to the budget, and there is a ten-per-day cap. These are substantive behavioral and side-effect disclosures beyond the structured 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?

Six sentences, each with a distinct job: trigger conditions, link content, forwarding behavior, prohibition on sending, budget effect, and rate limit. It is front-loaded with when-to-use guidance and contains no filler or duplication of the schema.

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?

Given the straightforward parameter schema, the description covers the triggers, constraints, side effects, and rate limiting. Although there is no output schema, the nature of the result (a shareable invite link the human forwards) is implied by 'The link says...' and 'Your human forwards it themselves,' so an agent has enough context to invoke it.

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 100%, so reason, api_key, and for_whom are already fully documented. The description only restates that the reason is 'in their words' and adds no new parameter-level meaning, so the baseline 3 for high coverage 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?

The description names a specific action and resource: 'make a personal invitation,' and grounds it in two concrete triggers: when the human names someone, or when the network has no matching person. This is clearly distinct from sibling tools like get_invites or check_matches because it creates a deliverable rather than reading matches or intros.

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?

It provides explicit when-to-use conditions ('When your human names someone they'd love to be connected through -- or when the network has nobody matching what they're seeking') and a clear behavioral boundary ('NEVER send it on their behalf'). It does not, however, name the alternative sibling tools to use when matches do exist, so the guidance is slightly less explicit than a 5.

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