chart_update

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

The description adds critical behavioral details beyond annotations: 'Anything left out keeps its current value' and 'an empty string clears a text field'. It also mentions position is kept. Annotations only indicate non-read-only and non-destructive, so the description carries the burden and fulfills it well.

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 sentences, front-loaded with the core behavior, then the prerequisite. No wasted words; the most important operational detail (keep/clear behavior) comes first.

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 complex 14-parameter tool with nested objects, the description covers the key behavioral aspects that aren't in the schema. It explains the general update model, how to obtain the ID, and references the 'clearing' mechanism. No critical gaps remain for an agent 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?

Schema coverage is 64%, so the description must compensate. It provides the overarching semantics: omitted fields retain current values, empty strings clear text fields, and valAxisScale replacement semantics are clarified. This goes beyond the schema's per-field descriptions and is essential for correct invocation.

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 action ('Reconfigure an existing chart in place') on a specific resource ('existing chart'), and distinguishes it from siblings by noting it keeps position. This clearly differentiates it from chart_insert (new) and chart_delete.

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 explicitly instructs to get chart_id from chart__list first, a clear prerequisite. It implies use only on existing charts, and the sibling list includes chart_insert for creation, so the when-to-use guidance is strong.

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