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

With no annotations, the description must carry the behavioral load. It does disclose that prices are live and that the response includes sizing constraints like the $10 minimum notional, but it says nothing about auth requirements, rate limits, pagination, or whether all markets are returned unfiltered.

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?

A single dense sentence with the core resource front-loaded and the concrete field names parenthesized at the end. Every clause earns its place, though the sentence fragment lacking an explicit verb makes it read more like a data label than an instruction.

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 zero-parameter listing tool with no output schema, the description successfully conveys the return shape (prices plus precision and minimum-size rules). The remaining gap is operational context such as whether the response is cached, whether prices stream or snapshot, and any auth expectations.

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 zero parameters, so there is nothing to disambiguate and the schema-side burden is nil. The description does not need to explain inputs, and the baseline of 4 applies.

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 the resource ('tradeable markets') and enumerates the payload (live prices, size_decimals, min_size, price rules, min notional), so an agent immediately knows what it gets. It stops short of a clear verb and never differentiates itself from sibling list_* tools, though no sibling actually overlaps on market data.

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?

Usage is only implied: the mention of 'precision metadata needed to size orders' hints this is a prerequisite lookup before place_order/submit_order. There is no explicit when-to-use statement, no exclusions, and no named alternative or prerequisite.

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