fetchMarkets

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

The description adds behavioral context beyond the readOnlyHint annotation by stating that it always hits the exchange API for live state. This informs the agent of the dynamic nature of results. No contradictions.

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?

Two succinct sentences. The first covers purpose and options, the second adds a key behavioral trait. No unnecessary words; every sentence earns its place.

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 14 parameters and no output schema, the description is minimal. It does not explain return structure, pagination nuances, or how to choose between this and fetchMarketsPaginated. The schema fills some gaps, but the description could be more complete.

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?

With 100% schema description coverage, the baseline is 3. The description does not add new meaning beyond the schema; it only summarizes the filtering options. The schema already describes each parameter, so no extra value from the description.

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 'Fetch markets' with optional filtering, search, or slug lookup, providing a specific verb and resource. It distinguishes itself from siblings like fetchMarket and fetchMarketsPaginated by implying a general fetch with multiple lookup options.

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 live data usage by saying 'Always hits the exchange API — results reflect the live state at the time of the call,' but it does not explicitly state when to use this tool versus siblings like fetchMarketsPaginated or fetchMarket. No exclusions or alternative suggestions are provided.

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