Price history

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description earns credit for what it adds: result ordering (oldest first), Tehran timezone, Rial currency, the absence of OHLC in Agah rows, and data-availability caveats for minute candles. Some of these caveats are duplicated from the schema parameter descriptions rather than being new information.

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 purpose statement followed by a tight comparison of the two shapes; nearly every sentence carries information. Minor deduction for a mid-sentence line break artifact and dense phrasing that makes the shape comparison read as a block.

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, the description correctly takes on the burden of explaining what is returned for each source, including field lists, ordering, timezone and currency. It stops short of covering pagination interaction between days and limit or behavior when a symbol is not found.

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%, so the enum values, defaults and limits are already fully documented. The description adds conceptual meaning about how source determines the returned shape, but gives no extra syntax or constraint detail for parameters like days/limit interaction. Baseline 3 applies when the schema does the heavy lifting.

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 ('Return price history of a stock') and immediately enumerates the two data shapes it can produce. It also distinguishes itself from br_index by name, so an agent can separate it from a sibling without opening the schema.

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 routes index queries to br_index and explains when each source mode applies (Mofid for OHLC, Agah for flow data). It does not address the boundary against other siblings like br_technical or br_quotes, so the guidance is clear but not exhaustive.

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