list_markets

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

Without annotations, the description discloses the read-only nature and lists the exact return fields (symbol, market_index, etc.). It does not mention pagination or rate limits, but for a simple list with no parameters, the behavioral description is adequate.

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 extremely concise: two sentences. The first sentence states the purpose, the second lists return fields. No wasted 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 tool's simplicity (0 parameters, no required input) and the presence of an output schema (fields listed in description), the description fully covers what an agent needs to know: what it does and what it returns. Sibling context is provided by the environment.

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?

There are no parameters (0 params, 100% schema coverage). The description adds no parameter info since none exist, meeting the baseline for a parameterless tool.

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 'List all tradeable perpetual markets on Lighter' with a specific verb and resource. It distinguishes itself from siblings like 'get_market' (singular) by indicating it returns all markets.

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 usage when needing a list of all markets, but does not explicitly state when to use it vs alternatives like 'get_market' for a single market. No exclusions or when-not-to-use guidance is provided.

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