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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, yet the description adds substantial context: results are chronological and truncated, coverage may be shorter than requested, adjusted history can change after splits or dividends, and 'unknown'/'null' field semantics are explained. This is exactly the extra context annotations cannot convey.

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 with purpose and budget-aware; nearly every clause carries new information. The telegraphic, semicolon-heavy style makes it slightly harder to scan than it needs to be, but there is no filler.

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?

There is no output schema, so the description must describe returns — and it does, covering truncation, source, stored-series update timestamp, actual candle dates, per-candle priceScale and adjustment metadata. Nothing an agent needs to call this correctly is missing.

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 coverage is 0%, so the description must carry all parameter meaning — and it does: 'up to 500 candles' (limit), '1-3650 calendar days' (days), and 'use ticker or ISIN' (symbol). It does not explain the interaction between days and limit when both constrain the result, leaving one real ambiguity.

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 and resource (returns stored GPW daily OHLCV price history) with explicit scope boundaries: equities only, excluding indices, ETFs and bonds, no intraday/live/supplier fetch. An agent can tell immediately this is the historical daily bar tool and not one of the unrelated siblings.

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?

Gives clear when-not conditions (no intraday, no live quote, no on-demand supplier fetch) and prescribes the identifier forms (ticker or ISIN). It does not name a specific alternative tool to use for intraday or live data, so the routing is broad rather than explicit.

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