get_historical_data

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

With no annotations, the description carries the full behavioral burden. It does disclose useful traits: periodicity defaults to DAILY, currency conversion is optional, and max_data_points truncates while keeping the most recent points. However, it says nothing about authentication/entitlement requirements, error behavior on invalid tickers or fields, or rate limits — significant gaps for an external data API call.

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 purpose sentence followed by a compact args list; every line adds information and nothing is repeated from the schema titles. The docstring format is conventional and easy to scan.

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?

An output schema exists, so return-value explanation is rightly omitted, and the parameter documentation is thorough enough to call the tool correctly. The remaining gap is environmental context — entitlement/auth needs and what happens on invalid tickers or unsupported field/periodicity combinations — for a tool with no annotations.

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 0%, so the description must compensate — and it does. It documents all seven parameters: example ticker and field formats, YYYY-MM-DD for both dates, the full accepted periodicity enum (WEEKLY/QUARTERLY/SEMI_ANNUALLY/YEARLY — not encoded in the schema), ISO currency conversion, and the truncation direction for max_data_points.

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 and resource ('End-of-period historical time series') and anchors it to the underlying BLPAPI HistoricalDataRequest / BDH() call, so the agent can distinguish it from get_intraday_bars, get_intraday_ticks, and get_reference_data. It does not explicitly name those siblings or route the agent between them, which keeps it 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?

Usage is only implied by the phrase 'End-of-period historical' — the agent can infer it beats the intraday siblings for daily-and-coarser time series, but no when-to-use, when-not-to-use, or alternative-routing guidance is given. There are also no stated prerequisites (e.g. resolving tickers via search_instruments, validating fields via search_fields).

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