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

Annotations already declare readOnly, idempotent, closed-world, so the safety profile is covered. The description adds genuinely useful context beyond that: the tool only produces a design/URL, the real phone-line build is a separate paid step confirmed on a call, and the design can be edited and voice-tested in-browser at no cost. It does not fabricate any mutation, so there is no contradiction with readOnlyHint; it could have gone further on what the returned design contains structurally.

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?

The core capability is front-loaded and the required inputs and downstream build step follow logically. It is slightly padded by promotional phrasing ('talk to the agent out loud in their browser for free'), but each sentence still carries usable information, so the cost is modest.

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 an 8-parameter tool with no output schema, the description covers the essentials: what is produced, what is mandatory, and what happens after. Since the output's shape (call flow + edit link) is described, the missing return-value documentation is a minor gap, as is the absence of an explicit get_agent_templates prerequisite.

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% with four documented enums, so the schema carries parameter semantics and a baseline of 3 applies. The description adds only the required-vs-optional distinction for industry and business_name, and no meaning for city, hours, pricing, services, add_steps, or emergency_transfer beyond what 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 description states a specific verb and artifact: it 'designs an AI receptionist' and enumerates the content of that design (step-by-step call flow, behavior at pricing/emergency/transfer points) plus the delivery mechanism (an editable link). That is far more concrete than a restated title. It does not, however, explicitly contrast itself with siblings such as get_agent_templates, which an agent might reasonably reach for first.

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 one actionable usage cue ('Only the industry and business name are required'), which tells the agent the minimal invocation. But it offers no when-to-use/when-not-to-use guidance and never names get_agent_templates as the prerequisite for resolving industry/service ids, so the agent must infer the ordering from the schema text alone.

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