Search eToro instruments by text

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

Annotations already cover read-only/idempotent/open-world safety, and the description adds real value on top: the return fields, the absence of images, the `limit`-bounded result count, and the non-obvious duplicate-ticker quirk (.RTH = regular-trading-hours instrument vs the plain 24/5 ticker). That quirk is exactly the kind of behavioral detail an agent cannot infer from structured fields.

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?

Front-loads what the tool does, then the return shape, then the ticker quirk, then the hand-off advice. Every sentence earns its place with no filler.

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 steps in to enumerate the returned fields and call out the image exclusion and duplicate-symbol behavior. An agent has everything it needs to call this correctly and to pass the result onward.

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 coverage is only 50% (limit has no description), so the description compensates: it clarifies that query matches by name or ticker and that limit caps the number of matches returned. The examples also disambiguate query format, though limit's max/min bounds are left to the schema.

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 (search) and resource (instruments) plus the search dimension (name or ticker), with concrete examples. It reads as distinct from a plain listing tool, but it never names the sibling (etoro_get_instruments) it differs from, so it stops short of explicit sibling differentiation.

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?

Gives clear context ('free-text search') and actionable downstream guidance: 'Use the instrumentId or the exact symbol with the other tools.' It does not state when NOT to use search versus a listing/lookup tool, so no explicit exclusions.

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