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

Annotations declare a non-read-only, idempotent, non-destructive write, and the description reinforces this by disclosing the state transition to 'scheduled' and the draft-only precondition, which is genuinely useful context beyond the annotations. It does not cover authorization needs, rate limits, or what happens on rejection of a non-draft id, keeping it below 5.

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?

Four short sentences, front-loaded with the action and resulting status, then constraints, then the precondition. No filler or repetition beyond minor overlap with the schema examples.

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 covers the action, the state change, parameter requirements, and eligibility. It omits error behavior for non-draft or past-dated input, which would round it out but is not essential to invoke the tool correctly.

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 the schema already documents all three parameters including the ISO 8601 example and IANA timezone. The description largely restates the same constraints (future ISO 8601 datetime, timezone for display) without adding new syntax or format detail, matching the baseline 3.

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 and resource ('Schedule a DRAFT broadcast'), plus the resulting state ('Sets the broadcast to scheduled status'). It clearly distinguishes itself from siblings like send_broadcast or cancel_broadcast by scoping to drafts.

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?

Gives a clear precondition ('Only draft broadcasts can be scheduled') and a constraint on the parameter ('scheduled_at must be an ISO 8601 datetime in the future'). It does not explicitly name an alternative tool (e.g., use send_broadcast to send immediately), so it stops short of a 5.

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