Add a chart

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond them: how the data range is interpreted (first column = X axis/labels, subsequent columns = series, header row supplies series names). It does not note permissions/account implications or that the chart is written into the sheet, which keeps it from 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?

Three tightly packed sentences with zero filler. The core action is front-loaded and the data-layout rules follow immediately in the order an agent would need them.

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 non-destructive mutation tool with no output schema, the safety profile is covered by annotations and the data-shape rules are explained, but chart_type/stacked behavior, the effect of omitting anchor_cell, and the return value are left entirely to the schema or unstated. Adequate, not complete.

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?

With 8 parameters at 50% schema coverage, the schema does only half the work. The description usefully clarifies the semantics of data_range and has_header (column-to-series mapping, header row for series names), but says nothing about chart_type, stacked, anchor_cell, title, or account choices. Partial compensation only.

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 gives a specific verb (Create) and resource (chart) plus the source of the data (a data range), which cleanly separates it from update_chart and delete_chart in the sibling list. It stops short of naming those siblings or otherwise explicitly stating the boundary, so it is clear but not maximally differentiated.

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?

Usage is only implied: an agent can infer 'use this when you want a new chart,' but the description never says when to prefer add_chart over update_chart, nor does it state prerequisites such as needing an existing data range with values. No explicit when-not or alternative is offered.

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