instrument

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

Beyond the `readOnlyHint` annotation, the description discloses important behaviors: `stats` is null for fresh instruments, case-insensitive lookup, venue-suffixed symbols pin specific listings, and the `radar` fingerprint. No contradictions with annotations.

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?

The description is well-structured with clear sections for each mode, uses bullet points for readability, and is information-dense without being verbose. Every sentence serves a purpose.

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?

Given the tool's complexity (dual mode), the presence of an output schema, and annotations, the description covers all necessary context: return values (null stats), case-insensitivity, venue pinning, and guidance to sibling tools. It is 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?

With 0% schema description coverage, the description must independently explain parameters. It thoroughly explains `symbol` and `asset_class`, but does not explicitly mention `limit`, `offset`, or `status` (though `status` is implied). This leaves some parameters underdocumented.

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 clearly states the tool's dual function: without `symbol`, it returns the catalog of covered markets; with `symbol`, it returns a single instrument's dossier with analytics. It distinguishes itself from sibling tools like `leaderboard`.

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?

The description provides explicit use cases for both modes, e.g., 'which markets do you cover?' and 'what do you know about AAPL?'. It also directs the user to `leaderboard` for strategy backtests on the instrument.

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