moex_market_snapshot

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered; the description adds genuinely new behavioral facts: one row per security, that large results are spilled to CSV, and the ~3000-row / ~7s cost of the corporate-bond case. It does not explain pagination or exact CSV trigger semantics beyond the default, but the added context is meaningful.

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-loaded with the core scope, then packed with concrete asset-class mappings and cost figures in a few dense sentences. Every clause carries information; the density is slightly at the expense of readability but nothing is wasted.

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 and 7 parameters, the description still covers the shape of the result (one row per security), the CSV fallback for large outputs, and the required market/board combinations. Return column semantics are left to the schema's columns parameter, which is acceptable given the ISS naming note.

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 57%, and market/board are bare strings in the schema, so the description does real work by supplying valid value pairs and the meaning of the index parameter (only the index base). The remaining params (columns, filename, save_csv, max_inline_rows) are already documented in 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+resource: it returns all securities in a trading mode with quotes, one row per security. The concrete market/board mappings (shares/TQBR, bonds/TQOB, bonds/TQCB) make the scope unambiguous, though it never explicitly names the siblings it differs from (e.g. moex_quote for a single security).

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 actionable routing guidance: which market/board combination to pick for stocks, OFZ, and corporate bonds, including the index=IMOEX caveat. It stops short of stating when NOT to use it or naming the better alternative for single-security lookups, so it is strong context rather than full when/when-not guidance.

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