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

The description adds behavioral context beyond annotations: 'can't be unsent' and 'outward-facing' indicate irreversibility and broad audience. Annotations mark destructiveHint false and readOnlyHint false, but the description clarifies the write nature and irreversible impact. It also notes 'host only' implicitly for access control.

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 concise with two sentences: the first covers the main action and delivery, the second covers usage guidance and caution. It is front-loaded with purpose and contains no unnecessary words.

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 no output schema and minimal annotations, the description is fairly complete. It covers the action, audience, channels, usage context, and an important warning. It could mention return value or ID, but that's not essential for invocation.

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 0%, so the description partially compensates by naming the three parameters (event_id, subject, message) and stating they are required. However, it does not explain constraints like lengths or formats beyond what the schema already provides.

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 clearly states the action (send announcement), the resource (all guests of a live event), and the delivery channels (email and in-app push notification). It distinguishes itself from sibling tools like send_invitations or cancel_event by specifying it's for announcements to all guests.

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 provides explicit when-to-use scenarios (time/venue change, reminder, thank-you) and a strong caution that the announcement can't be unsent, advising confirmation with the host. It does not explicitly name alternatives, but the usage context is clear.

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