chart_scroll_to_date

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

Annotations already declare readOnlyHint=false and idempotentHint=false, so the agent knows this mutates chart view state and is not repeat-safe. The description adds a useful post-condition ('verify it is visible') and the requirement that a visible span already exist, but says nothing about what happens on failure or whether the scroll is animated/awaited.

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 compact sentence with the operation front-loaded and no filler. The trailing 'and verify it is visible' is terse and slightly ambiguous, which keeps it from a 5.

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 mutating tool with no output schema, the description covers the core action and one post-condition but omits failure behavior (e.g., timestamp outside loaded data), whether the call blocks until the scroll settles, and what the verification result looks like to the agent.

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 100%, so all three parameters are already documented, including 'Unix seconds' for time and the layout-ID guard. The description's mention of 'Unix-second timestamp' merely restates the schema and adds no new semantics for target_id or expected_layout_id. Baseline 3 applies.

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 ('Centre') applied to a specific resource ('the existing visible span') on a chart, anchored to a Unix-second timestamp. The phrase 'existing visible span' implicitly distinguishes it from range-setting siblings like chart_set_visible_range, though no sibling is named.

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?

Using 'the existing visible span' implies this is a pan operation that preserves the current zoom, which hints at when to prefer it over chart_set_visible_range, but that guidance is only implied. There are no explicit when/when-not statements or named alternatives.

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