list_markets

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

With no annotations, the description carries the full burden. It states that the tool lists 'all' markets, which is a useful scoping detail. However, it does not mention return format, pagination, authentication, or potential side effects. For a simple read/list tool, this is adequate but not rich.

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 two short sentences, front-loaded with the primary purpose. Every sentence earns its place: the first states what the tool does, the second explains how to use the result. No unnecessary words.

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?

Given the simplicity of the tool (no parameters, no output schema, no annotations), the description is complete enough. It states the endpoint's purpose and provides a usage hint. It does not detail return fields beyond mentioning IDs, but for a list-all tool this is sufficient.

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 has zero parameters, so the description does not need to elaborate on input semantics. The baseline for 0-param tools is 4, and the description adds helpful context about the output (market IDs) rather than input 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 the tool's function: 'List all stock markets (exchanges).' This uses a specific verb and resource, and distinguishes it from siblings like list_countries or list_instruments. The additional note about using market IDs for filtering reinforces its unique role.

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 provides clear context for when to use this tool: to obtain market IDs for filtering instruments. While it does not explicitly exclude alternatives or name sibling tools, the purpose is clear enough that an agent would know to use this when market IDs are needed.

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