Check eToro trading eligibility

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

Annotations already cover readOnlyHint, idempotentHint, destructiveHint and openWorldHint, so the safety profile is known. The description still adds genuine value by stating 'Computes only; places nothing' and by describing the returned decision fields (settlement types, permissions, limits), which no output schema provides. It does not, however, cover auth scope or any per-call limits beyond input count.

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 dense clause stating what is returned, followed by a short constraint sentence and a short input instruction. Strongly front-loaded with the payload description and no filler. Slightly run-on list inside the first clause, but nothing is wasted.

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 0% schema description coverage, the description must explain both returns and inputs, and it does so competently for a two-parameter read tool. Remaining gaps are minor: behavior when neither parameter is given, and the 'demo account' scoping, which could confuse an agent unsure whether it applies to live accounts.

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?

Schema description coverage is 0%, so the description must carry the parameter burden and largely does: it explains that instrumentIds and symbols are alternatives ('and/or') and imposes a 'max 100 combined' limit that is stricter and more useful than the schema's per-array maxItems of 100. It does not explain symbol format or what happens when neither is supplied.

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 enumerates exactly what the tool returns for a given instrument set (settlement types, leverage, buy/sell and partial-close permissions, minimums, SL/TP limits), which is far more specific than a restatement of the name. It is clearly distinct from the portfolio/pnl/balances siblings. It lacks an explicit verb ('check'), but the resource and scope are unambiguous.

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 implied rather than stated: the tool reports what an account may trade, and 'Computes only; places nothing' signals a pre-trade query. However, there is no explicit when-to-use framing, no prerequisites, and no alternative sibling is named or excluded, so an agent must infer the context.

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