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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description still adds genuinely useful behavior: the warm-up on price history fetched before startDate means values are stable regardless of the requested range's left edge, plus the exact output columns (%B, bandwidth). That is real context beyond the annotations.

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?

Reasonably front-loaded, but a full sentence is spent on general indicator education (bands widen when volatility rises, touching bands is an overbought/oversold cue) that does not help an agent select or call the tool. The warm-up note is the only sentence that clearly earns its place.

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 compensates by naming the returned columns (%B, bandwidth, bands). All six parameters are documented in the schema, and the warm-up caveat removes a subtle correctness pitfall. Only the absence of routing guidance against siblings keeps it from a 5.

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 100%, so the schema already documents period, stdDev, ticker, dates and maxResults, making 3 the baseline. The description clarifies the derived columns and the date-warmup semantics, but adds nothing about period/stdDev syntax or date formatting beyond what the schema states.

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 resource (Bollinger Bands for a stock) and even defines the computation (SMA of close plus upper/lower bands at N standard deviations). An agent knows exactly what it gets. However, it never distinguishes itself from the sibling technical indicators (GetAverageTrueRange, GetStochasticOscillator, GetOnBalanceVolume), so it stops 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?

The description explains what the indicator means but never says when to reach for it versus the other technical-indicator siblings or GetStockPrices. The overbought/oversold remark is interpretive background, not routing guidance, and there are no prerequisites or exclusions stated.

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