chart_set_timeframe

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

With no annotations, the description carries the full burden and does well: it flags STATE_MUTATING, cache invalidation, state-generation increment, and that the call blocks until candle feed resolution. It omits failure modes (unsupported timeframe, no active chart) and any permission/precondition requirements.

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 the core action, then labeled sections for usage, side effects, and limits. Slightly dense in the parenthetical side-effect block, but no sentence is 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?

One required parameter, no output schema, and the description covers usage, mutation semantics, blocking behavior, and accepted formats. Remaining gaps (what happens on an invalid timeframe, whether a chart must already exist) are modest.

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% (baseline 3), and the LIMITATIONS line adds value the schema lacks — the schema declares no enums, so the explicit list of standard minutes ("1","5","15","60","240") and calendar periods ("D","W","M") is genuinely additive.

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 first sentence gives a specific verb (change) plus resource (chart timeframe/resolution) and adds the blocking behavior, which distinguishes it from sibling chart_get_multi_timeframe (read-only multi-series) and chart_set_symbol/chart_set_type.

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 WHEN TO USE line gives a concrete trigger (switching resolutions for multi-timeframe analysis) with an example (1D to 15m). It does not, however, name an alternative or exclusion — e.g. it never says to use chart_get_multi_timeframe instead when you only want to read several resolutions without mutating state.

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