moex_index_constituents

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds nothing behavioral: it says nothing about output shape (SECID/WEIGHT columns), CSV side effects, or the inline-row cap that the schema parameters imply. Given the lower bar with annotations, this is thin rather than contradictory.

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?

A single compact line with the key information (composition + weights + supported indices) front-loaded and no filler. It is terse to the point of being a fragment, which slightly limits 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 six optional parameters and no output schema, the description should say more about what is returned (membership rows with weights) and how the CSV/inline-row options behave. It covers which indices are supported but leaves the return content to inference.

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 83%, so the schema carries most parameter meaning. Crucially, the one undocumented parameter (indexid) is compensated for by the description enumerating the valid index identifiers (IMOEX, MOEXBC, RTSI, RGBI, sectoral), which is genuine added value beyond 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?

The description names the resource (index composition) and the payload (weights in %), and enumerates the covered indices (IMOEX, MOEXBC, RTSI, RGBI, sectoral), which cleanly separates it from siblings like moex_security or moex_quote. It is a noun phrase rather than a verb+resource sentence, and it never contrasts itself with those siblings, so it stops short of a 5.

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?

There is no explicit when-to-use guidance, no prerequisites, and no named alternative among the 14 sibling tools. The agent must infer that this tool is for index membership rather than for quotes or security metadata, so usage is only implied.

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