get_index_performance

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

With no annotations, the description carries the full burden. It is transparent about the output content and the grouping scope, which is helpful, but it does not mention response size, sorting, pagination, or any operational constraints. For a read-only snapshot tool this is acceptable but not rich.

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 two compact lines with no filler: one line states the output, the other states the filter options. It is front-loaded, scannable, and every sentence earns its place.

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?

For a tool with one optional parameter and no output schema, the description supplies the essential call semantics: the return metrics, scope, and group filter. The only notable gap is that the group categories are not explained, but this is minor for constructing a valid call.

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?

The input schema provides only a bare string parameter with 0% coverage, so the description must compensate. It does enumerate the allowed group values (all, broad, sectoral, thematic, strategy), which lets an agent form a valid call, but it does not define what each group category means.

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 identifies the resource ('All NSE indices') and the exact data returned (last value, % changes, PE, PB, dividend yield). This is enough to distinguish it from siblings like get_index_constituents, though it does not explicitly name an alternative.

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 'group: all | broad | sectoral | thematic | strategy' line provides useful filtering context and implies this is the tool for index-level performance snapshots. However, it does not explicitly say when to use it versus related tools such as get_index_constituents or get_market_pulse.

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