get_available_markets

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

With no annotations present, the description carries the behavioral burden. It clearly indicates the tool reads market data rather than mutating anything, and it adds a significant availability caveat about the Spotify API change. It could mention what actually happens when the tool is called on a newer registration, but the deprecation status itself is meaningful 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 only two sentences: the first states the operation and scope, the second adds a crucial availability warning. Every sentence earns its place, and the core purpose is front-loaded.

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 simple list tool with fully documented optional parameters, the description provides the output type (country codes), the scope (every market), and an important availability caveat. It does not explicitly state what error or fallback behavior occurs when unavailable, and it does not point to an alternative, but the overall picture is sufficient for a competent agent.

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 both max_results and response_format already documented in the input schema. The description adds no parameter-level detail, but it is not required to compensate because the schema explains the parameters fully. Baseline 3 is appropriate.

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 names a specific verb and resource: it lists the country codes of every Spotify market. This clearly distinguishes a broad availability-list operation from the more targeted market_validate and market_availability siblings. The deprecation note is a useful extra but does not obscure the core purpose.

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 when not to use the tool by stating it was removed and is unavailable for newer app registrations, but it does not explicitly state when to use it or name a preferred alternative. The usage context is clear enough to avoid obvious misuse, but the routing guidance is left to inference.

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