market_latest_barsRetrieves the current one-minute price bar for each requested stock ticker, returning USD prices and share volume for up to 200 symbols.
The latest one-minute bar for each stock ticker (prices USD, volume shares).
| Name | Required | Description | Default |
|---|---|---|---|
| tickers | Yes | Stock tickers, e.g. ["AAPL", "BRK-B"] (1-200). |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely useful semantics (prices in USD, volume in shares), but says nothing about freshness/latency of the 'latest' bar or partial-day behavior.
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 front-loaded sentence with no filler; the units parenthetical is the only extra clause. Appropriately sized, though it errs toward under-specification rather than verbosity.
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 simple one-parameter read tool this is close to adequate, but with no output schema the description could have said what a 'bar' contains (OHLC fields) or how fresh the latest bar is. Those gaps are minor but real.
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?
Only one parameter and schema description coverage is 100% — the schema already documents the ticker format, example, and the 1-200 bound. The description adds no parameter-level meaning beyond what the schema provides, so baseline 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 states a specific verb (return/latest), resource (one-minute bar) and scope (for each stock ticker), which cleanly separates it from quote/trade siblings. It does not explicitly name the sibling it differs from (e.g. market_bars for history, market_latest_quotes for quotes), so differentiation is implied rather than stated.
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 when-to-use guidance at all: nothing says to pick this over market_bars (historical bars), market_latest_quotes, or crypto_latest_bars. The agent must infer the choice from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.