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

Annotations already declare this is read-only and idempotent. The description adds useful context by explaining the state includes every indicator and drawing with instance IDs, and that after modifications the tool can be re-called to confirm what landed. This goes beyond annotations without contradicting them.

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?

Two dense sentences with no filler. The content and primary use case are front-loaded, with the follow-up action (chart_link) placed at the end. Every clause 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?

For a zero-parameter read-only state tool, the description covers what the state contains, why an agent would call it, when to call it again, and the follow-up tool to use. No additional behavioral or return-value information is needed for correct invocation.

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 has no parameters, and the input schema reflects that with an empty properties object. There is nothing for the description to add about parameters; the baseline of 4 applies, and the description appropriately focuses on the returned state rather than parameters.

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 the exact resource—the chart state for a specific person—and enumerates its contents: venue, symbol, timeframe, chart type, indicators with instance IDs, and drawings. It also states an explicit use case, retrieving instance IDs, which distinguishes it from chart_* sibling actions like chart_set_instrument or chart_add_indicator.

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?

It gives explicit when-to-use guidance: 'Start here when you need an instance id' and 'call it again after changes to confirm what landed.' It also directs the final step to chart_link. It lacks explicit when-not-to-use or alternative comparisons, but the context is clear enough for an agent to decide when to invoke it.

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