List services

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

Annotations already mark this as read-only and open-world, so the safety profile is covered. The description adds valuable behavioral context: results are live, include price/stock, and the unfiltered response can be very large, which meaningfully informs how an agent should invoke the tool.

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?

Three short sentences, each earning its place. The most important guidance (filter to avoid huge result sets) is front-loaded, and no redundant phrasing is present.

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 description covers the key invocation requirements, including parameter semantics, filtering preference, and result expectations. There is no output schema, so the exact return shape is not fully specified, but the mention of live price and stock gives an agent a sufficient mental model.

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 baseline is 3. The description goes beyond the schema by explaining what the codes mean ('tg' for Telegram, '6' for a country code) and by reinforcing the filtering purpose of the optional 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 clearly states a specific action ('List buyable services') and adds distinguishing details: live price and stock. It is easy to tell apart from sibling list_countries because it operates on buyable services rather than static country codes.

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 gives clear operational guidance by strongly recommending filtering by service and/or country due to the large unfiltered catalog. It does not explicitly discuss when to choose this tool over a sibling, but the domain is distinct enough that no exclusions are necessary.

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