find_instrument

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

Annotations already cover readOnly, openWorld, idempotent, and non-destructive hints. The description adds that it returns a list of candidates with specific fields (ticker, board, figi, secid, name, type, currency), which is useful behavioral context. It doesn't contradict 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 compact: two sentences that state purpose, usage triggers, and return fields. No fluff, and the most critical information (purpose) is front-loaded.

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?

The description covers purpose, when to use, and what is returned. It doesn't mention pagination or disambiguation strategies, but the output schema likely covers return structure, and the tool's simplicity means these gaps are minor. It is sufficient for an agent to call 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 provides descriptions for query and kind, but limit has no description. The tool description does not add parameter-level detail beyond what the schema already says (e.g., query accepts ticker/name/ISIN). With 67% schema coverage, the description doesn't compensate for the missing limit semantics, but limit is a simple numeric bound so this is acceptable.

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 verb 'найти' and the resource 'биржевой инструмент', specifying it searches by ticker, name, or ISIN. It also distinguishes itself from sibling tools by framing it as a lookup/fallback tool, not a data retrieval tool like get_quote or get_candles.

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 states when to use: when the user mentions a company by name or when another tool returns instrument_not_found / ambiguous_instrument. This gives clear conditions and implies the alternative (other tools) without naming them, which is sufficient for routing.

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