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

Beyond the annotations (which only declare it is a non-read, non-destructive, open-world write), the description discloses the 10-blast-per-event cap, the delivery fallback for email-invited guests, the confirmation requirement, the credential needed, and confirmation of reach before contacting others. That is exactly the extra behavioral context annotations cannot carry.

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?

Front-loaded with what it does and the blast cap, and most sentences earn their place. The confirmation rule is spread across two adjacent sentences, which is mildly redundant, but overall tight for the amount of behavior communicated.

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 no output schema, the description still tells the agent what is returned (how many people reached, how many blasts remain), the credential requirement, and the confirmation protocol, so nothing needed to invoke it correctly 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% and already documents all three params, so baseline is 3. The description adds meaning by explaining the delivery mechanics tied to the statuses selection and the guest-reach behavior, going slightly beyond the schema's terse 'Who receives it' note.

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?

It names a specific verb and resource (text a message to guests by RSVP status) and pins down scope by equating it to 'New Blast on the event page'. An agent can tell this apart from partiful_invite_guests or partiful_list_guests without opening any schema.

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 gives strong operating context: guests must be RSVP'd or invited through Partiful, email-invited guests are reached by email, and a per-call confirmation is required by default. It stops short of explicitly contrasting with the sibling invite/list tools, so the when-not-to-use case is left implicit.

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