fetch_markets

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

With no annotations, the description carries the full burden and does disclose the key behavioral traits: this is a read-only public call needing no credentials, and it returns static definitions rather than live summary stats. It stops short of covering pagination, response size, or error behavior, which are minor for a zero-parameter listing.

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: what it returns, the auth posture, and the routing hint. The most decision-relevant content (static specs vs live stats) 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?

With no output schema and no parameters, the description should convey what comes back, and it does by naming the returned fields (tick size, lot size, leverage, contract details). Nothing essential is missing, though the field list is illustrative rather than exhaustive.

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 takes no parameters, so there is nothing for the description to clarify beyond confirming the call is unconditional. Baseline of 4 applies for a 0-parameter 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?

States a specific verb and resource ('List all markets') and immediately enumerates what the listing contains (tick size, lot size, leverage, contract details). It explicitly separates itself from fetch_markets_summary, so an agent can pick the right tool without opening a schema.

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?

Gives both the positive condition (static specs, no live stats) and the explicit alternative ('Use fetch_markets_summary for live mark price / volume / funding'). It also states the auth posture (public, no credentials), which is actionable routing information.

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