schedule_message

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the write/side-effect profile is covered structurally. The description adds the 120-day scheduling limit, which is useful context, but it does not explain the odd 'destructive' classification, required channel/text content, per-channel permission needs, or what identifier is returned for later cancellation.

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?

Two short sentences, zero filler, with the action and its hard constraint front-loaded before the format hint. Nothing repeats the schema or annotations.

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?

For a four-parameter mutation with no output schema and no annotation nuance, this is thin: it omits thread reply behavior, channel targeting semantics, and what a successful call yields so the message can be found or cancelled later. The post_at clarification is the one substantive addition.

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 0% for four parameters, so the description must carry the load and it only partially does: post_at is genuinely clarified ('Unix seconds or ISO-8601 with offset'), which the bare string schema does not convey. channel, text, and especially thread_ts remain undocumented (e.g., whether channel accepts an ID or name, what a thread_ts value is).

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?

Specific verb + resource ('Schedule a message') with a stated horizon constraint (up to 120 days ahead), so the action is unambiguous. It does not differentiate from the closest siblings, conversations_add_message (send now) and list_scheduled_messages / delete_scheduled_message, which an agent must choose between.

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?

No when-to-use or when-not-to-use guidance is given. The description never mentions that this is the delayed counterpart to conversations_add_message, nor that scheduled messages are later managed via list_scheduled_messages / delete_scheduled_message.

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