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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe, non-destructive read operation. The description adds useful behavioral context: the tool returns a one-line embed code, the snippet places a chat button that supports chat, voice, WhatsApp, and Telegram, and the agent answers questions, takes messages, and handles booking requests. It doesn't mention auth, rate limits, or response formatting, but with annotations covering safety, this is sufficient for a 4.

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 description is front-loaded with the core action in the first sentence, which is good. However, the second sentence is a long run-on list of capabilities, platforms, and search terms, and 'Free to start' is promotional filler that doesn't help invocation. It is understandable but not tight.

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?

There is no output schema, but the description explains that the return value is a one-line code snippet and describes what that snippet enables. Both parameters are documented in the schema, and annotations cover the safety profile. It is nearly complete for an agent to call correctly, with only minor gaps around exact return format and prerequisites.

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%, so the schema already fully documents both parameters, including the link format and the supported site values. The description adds the practical instruction to give the person's fone.me link if they have one, but otherwise repeats information already present in the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 clearly states a specific verb and resource: get the one-line code that embeds a fone.me AI agent chat button on a website. It also explains what the button does (chat, voice, WhatsApp/Telegram) and what the agent handles. It doesn't explicitly differentiate from the sibling tools find_agents, get_agent, and message_agent, so it stops short of 5.

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 clear usage condition: someone building or editing a website who wants a chatbot, AI receptionist, live chat, or contact widget. It names many supported platforms and says to provide the fone.me link if available. It doesn't state when not to use it or name alternatives, which keeps it at 4.

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