Market indices

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered structurally. The description adds only the 'today' currency framing; it says nothing about result size, pagination, or what market state/trading totals actually contain. Adequate but thin given annotations carry most of the burden.

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?

Two sentences, both front-loaded with the highest-value information: what it returns, then when to use it and where to go for history. No filler or restatement of the title.

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 2-parameter, zero-required, read-only listing tool with no output schema, the description covers purpose, scope and sibling routing sufficiently to invoke correctly. Only minor gaps remain around result volume and the meaning of 'market state'.

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 description coverage is 100% – both `limit` ('max indices, strongest change first') and `query` (with Persian example fragments) are well documented in the schema. The description adds no parameter detail of its own, so the baseline of 3 applies.

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 specific resource and its contents precisely: TSE total index, market state, trading totals, and every sector/market index with its change. It is clearly distinguishable from ts_index_history, though the verb is implicit (it describes the payload rather than saying 'lists'/'returns').

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?

It gives an explicit use case ('Use to see which sectors lead or lag today') and routes the agent to the correct sibling for historical values ('Pass an index name to ts_index_history for its past values'). It does not address overlap with other siblings like ts_market_movers, so it stops short of full when-not-to-use coverage.

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