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

With no annotations, the description carries the disclosure burden well: it states the default behavior when bounds are omitted (whole history at that step), the failure mode for oversized windows (explicit refusal, never silent truncation), and the data-end clipping rule. It stops short of stating rate limits, response envelope, or whether values are adjusted, which keeps it off a 5.

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?

Dense and front-loaded, with the primary purpose in the first clause and the sibling routing immediately after. It loses a point for referencing "the tools above" and "none of them," positional phrasing that ages badly, and for a couple of illustrative size facts (five thousand bars) that sit close to the line of padding.

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 4-parameter read tool with no output schema and no annotations, the description supplies the return shape (OHLCV), defaults, time-bound semantics, refusal behavior, and data-end clipping. Remaining gaps — auth expectations, maximum servable window in concrete terms, and response encoding — are modest 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?

Schema coverage is already 100%, so the baseline is 3; the description earns above baseline by adding cross-parameter meaning the schema cannot express — `asset` must come from list_coverage and `step` must be one of that asset's scales, with the example that a daily asset only has `1d`. It also clarifies that omitted `since`/`until` means unbounded history rather than an error.

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 a specific verb and resource ("Get the bars themselves — open, high, low, close and volume at a fixed step — for a stretch of time") and explicitly distinguishes itself from get_market_state (moment vs history) and get_price_paths (path as percent). The agent can identify the tool's role 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?

"Reach for it when the tools above do not shape the data the way you need it" defines the escape-hatch use case, and the two named alternatives each get a selecting condition. It also gives practical gating rules: BTC at 1h needs a `since`, and an oversized window is refused rather than truncated.

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