chart_get_snapshot

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

With no annotations supplied, the description carries the full behavioral burden and does so well: 'SIDE EFFECTS: None (Read-only)' declares the safety profile and 'LIMITATIONS: Lightweight snapshot only' scopes what it will not do. It omits any note on response timing, staleness guarantees, or error behavior, which keeps it below 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?

Roughly three front-loaded clauses with labeled WHEN TO USE, SIDE EFFECTS, and LIMITATIONS sections. Every sentence carries distinct information and the core action plus returned fields lead the text.

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 and no annotations, and the description compensates by listing exactly which fields the snapshot contains plus its read-only, lightweight nature. For a zero-parameter read tool, an agent has everything needed to call it correctly.

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?

The tool takes zero parameters, so the schema baseline of 4 applies; there are no argument semantics for the description to clarify or compensate for.

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 ('Get authoritative atomic snapshot of chart state') and enumerates the returned fields (symbol, resolution, lastBarTime, barCount, generation ID), making the tool's scope concrete. However, it never names sibling chart_get_state or chart_get_state_diagnostics, so an agent cannot be fully certain which state-reading tool to pick without opening schemas.

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 explicit 'WHEN TO USE' clause gives clear context: verify state freshness or obtain atomic synchronization metadata without pulling full bar series. The 'Lightweight snapshot only' limitation implies when not to use it, but no alternative sibling is named as an explicit substitute, so it stops short of full when/when-not guidance.

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