List research instruments and coverage

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

Beyond readOnlyHint and openWorldHint, it reveals determinism, cost-free access, authoritative derivation, excluded symbol-day visibility, and the Binance perpetual mapping for NVDAUSDT/QQQUSDT. This is far richer than annotations alone, with no contradiction.

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?

Dense but efficient; every sentence contributes value. It is somewhat long due to explaining three modes and an overflow warning, but that complexity justifies the length.

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 fully explains return modes, content of each mode, size constraints, determinism, cost, and edge cases. It provides all necessary context for an agent to invoke and interpret results correctly.

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 100%, yet the description adds substantial meaning: default output fields, per-symbol record contents, lowercase convention, string-array repair, and ETag projection scoping. This goes well beyond the schema's own property descriptions.

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 returns the authoritative feature-store universe from complete manifests, with distinct modes for summary, specific symbols, and full bytes. This specific verb+resource clearly distinguishes it from siblings like list_features.

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?

Provides explicit mode selection guidance: default compact summary avoids context overflow, symbols for specific canonical records, full for verbatim bytes. However, it does not explicitly name alternative tools for when not to use this one, so a small gap remains.

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