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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds value by disclosing the return format ('crypto_perp:bybit:BTCUSDT', 'equity:NASDAQ:AAPL') that no output schema provides. It omits ranking/ambiguity behavior for multi-match queries.

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 tight sentences: coverage first, then the return-value contract and its consumer. Nothing is repeated from the title or schema and every clause 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?

For a one-parameter lookup with no output schema, the description supplies the critical missing piece: the shape of the returned id. Coverage list plus id format is nearly enough; match-ranking or case-sensitivity behavior would close the remaining gap.

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 100% and the single query parameter is fully documented there with examples. The description adds no syntax or matching-semantics detail (prefix vs fuzzy vs exact) beyond what the schema already states, so baseline 3 applies.

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 (Find) and resource (any instrument OwlChart covers), then enumerates the asset classes covered, which cleanly separates it from siblings like get_price_history or get_etf_flows that act on a single market type.

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?

Explicitly frames the tool as the lookup step whose output ids feed into get_price_history, giving clear downstream context. It stops short of stating when NOT to use it (e.g. when an id is already known), 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.