fetch_markets_summary

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

With no annotations, the description carries the full behavioral burden; it does usefully disclose that the endpoint is public and requires no credentials, and it names the returned fields. It does not say whether the call is rate-limited, paginated, or how large the response may be, and read-onlyness is only implied by 'List'.

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, front-loaded sentence plus an auth note, with no filler. The most useful information (what it lists and what fields it returns) comes first.

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 trivial zero-param, no-auth listing tool with no output schema, the description adequately covers the return payload and access model. The remaining gap is sibling disambiguation, which no output schema or annotation would have supplied anyway.

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 per the rubric the baseline is 4 and there is nothing for the description to compensate for. No parameter information is missing or required.

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 (List) and resource (tradable markets) and enumerates the payload (mark price, 24h change, volume, open interest, funding), so the agent knows what data comes back. However, it does not distinguish this from near-identical siblings such as fetch_markets, list_markets, fetch_tickers, or fetch_mark_price, which is the main disambiguation need here.

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?

There is no when-to-use, when-not-to-use, or named alternative guidance at all, despite a crowded sibling set of market-data tools. 'Public — no credentials needed' hints at the auth context but does not tell the agent why to pick this tool over fetch_tickers or fetch_markets.

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