List services

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

With no annotations provided, the description carries the burden of disclosing behavioral traits. The verb 'List' implies a read-only operation with no side effects, and the mention of 'prices' indicates the return value includes pricing. For a simple listing tool, this is sufficient transparency.

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 one sentence, front-loaded with the verb and object, and includes helpful examples ('WhatsApp, Telegram, Google, Discord, etc.'). No unnecessary words, perfectly concise.

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?

The tool is simple: no parameters, no output schema, and a clear listing purpose. The description fully covers what the tool does and what it returns (services and prices), and the sibling tools provide surrounding context. Nothing essential 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?

The tool accepts zero parameters, and the input schema is empty, so schema coverage is 100%. The description correctly omits parameter details, as there are none to explain. A baseline of 4 applies for tools with no parameters.

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 uses a specific verb ('List') and a clear resource ('services sms-florin can rent a UK phone number for'), with examples and pricing. It clearly distinguishes itself from sibling tools like rent_number and get_rental, which perform different actions.

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?

The description implies the tool is for browsing available services and their prices before renting. It doesn't explicitly state when not to use it or name alternatives, but the purpose is self-evident given the sibling tool names and context.

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