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

Annotations only declare this is a non-read, non-destructive, non-idempotent create; the description adds the crucial behavioral fact that the notification fires to the caller, not the prospect, and that nothing is sent externally. That is real context beyond the structured fields. It stops short of warning that repeated calls produce multiple reminders (the non-idempotent trait), leaving that inference to the agent.

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, each doing distinct work: purpose, recipient semantics, negative scope, cancellation. The core behavior is front-loaded in the first sentence with zero restatement of the title.

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 6-param create tool with full schema coverage and no output schema, the description covers recipient semantics, scope exclusions, and cleanup. It doesn't say what a successful call returns (e.g., the new reminder's id), which would close the last gap in a create-then-reference workflow.

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%, so baseline is 3; the description earns above that by clarifying who `remindAt` notifies ("You are notified at `remindAt` — you, not the prospect"), which the schema's format note (epoch ms or ISO 8601) does not convey. Remaining params are fully documented in-schema.

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 ("Set a follow-up reminder on a lead or conversation") and immediately delimits scope against lookalike operations: it does not schedule or delay a campaign step. An agent can separate it from campaign_* and lead_update 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?

Explicit when-not clauses: it is not a campaign step, and if the goal is to make a lead wait, use `lead_update` with `paused`. It also names the cancel path (`reminder_delete`), so both the alternative and the reversal are routable.

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