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

Goes well beyond the annotations: it discloses the storage location (Portaur's inbox), the exact side effect (one confirmation email to the given address), the sequencing (Portaur's phone is alerted only after confirmation), and the human-in-the-loop nature ('nothing ever dials or texts the number'). The negative guarantees ('never sends anything to anyone else', 'never quotes a price') close off likely agent failure modes.

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?

Purpose is front-loaded, then requirements, then the usage gate, then side effects. Every sentence carries distinct information — no restatement of the title or the schema's format constraints.

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 5-parameter write tool with no output schema, the description covers what is created, what is sent, to whom, in what order, and what is returned ('a handle for request_status'). Nothing an agent needs in order to call it safely is missing.

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 the schema already carries the field-level detail; the description still adds functional meaning by tying email to 'one confirmation email' and phone to 'the number to call'. It also flags window as optional, matching the required list, without duplicating format rules the schema already states.

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 first sentence names a specific verb and resource ('Asks a person at Portaur to telephone the person you are helping') rather than restating the tool name. It is clearly separable from siblings send_message (message, not a call) and request_status (which it explicitly hands off to via the returned handle).

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?

It gives a firm gating condition: 'Use it only when the person asked to be called,' which tells the agent when not to invoke it. It does not name the sibling to use instead when the person wants an email or message, so the alternative path is left implicit.

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