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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered. The description adds nothing beyond them: no note on payload size, whether the list is paginated or filtered server-side, or how frequently the symbol set changes.

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?

One short sentence, front-loaded with the verb and the resource. No filler text, no restatement of the tool name, nothing to trim.

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, the description carries the burden of describing the return value, and it does not — the shape of a returned symbol (symbol id, base/quote, category, tradability flags) is unknown. For a simple no-arg enumeration call the gap is survivable, but it is not 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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter semantics for the description to clarify or omit.

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 clear verb+resource ('List all available TradFi trading symbols') with an explicit scope qualifier ('all available'). It is distinguishable from cex_cfd_query_symbol_kline and cex_cfd_query_symbol_ticker, which act on a single symbol, but it never names those siblings or the boundaries between them.

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: an agent can infer this is the discovery call to enumerate the tradable CFD universe before calling the kline/ticker siblings. There is no explicit when-to-use, no exclusion, and no mention of the closely related cex_cfd_query_categories tool.

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