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

Annotations only state it is a non-read-only, non-idempotent, open-world write. The description adds materially more: the message reaches a real end client, the delay range is one minute to one month, the action cannot be undone once sent, and editor role is required. These are exactly the behavioral facts an agent needs before triggering an external, irreversible effect.

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?

Three short sentences, front-loaded with what the tool does, followed by the irreversible-effect warning and the role prerequisite. No filler and nothing repeated from 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, the description covers the essentials: effect, reversibility, prerequisite role, and timing bounds, and the annotations cover the safety profile. It stops short of noting that retries will create duplicate scheduled sends (idempotentHint=false) or pointing at dosai_list_scheduled_messages for review/cancellation.

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 each parameter is well documented (send_at format, UUID sources), so the baseline is 3. The description nonetheless adds a constraint absent from the schema, namely the valid send_at window of one minute to one month, which is genuine extra semantic value.

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 ('Queue a message'), the target ('a REAL client'), and the scheduling window ('from a minute to a month ahead'). This implicitly separates it from the immediate-send sibling dosai_send_operator_message and from test/mock paths like dosai_test_bot, so an agent can route correctly 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?

Gives concrete pre-call guidance: confirm wording and time with the user because the send is irreversible, and confirms the prerequisite ('Requires editor role'). It does not name an explicit alternative for immediate sends or for canceling/rescheduling, which is what a 5 would require.

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