Update a chart

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorld=true), and the description adds the non-obvious patch semantics that unspecified fields are left untouched. It does not mention permission requirements or what the response looks like, so it is good but not complete.

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 short sentences: the mutation scope first, then the key behavioral rule, then the id source. Every sentence earns its place with no filler.

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 an 11-parameter mutation tool with no output schema, the description covers the critical unknowns: what changes, what is left alone, and where ids come from. Missing only secondary details like auth/permission notes.

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 64% schema coverage across 11 parameters, the schema does much of the work, and the description maps its facets onto the parameters (title, type/data_range, stacking, position/anchor, size) and documents chart_id provenance. The remaining parameters (account, has_header, spreadsheet) are only covered by the schema, so it adds value without full compensation.

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 ('Change an existing chart') and enumerates the editable facets (title, type, data range, stacking, position, size), which cleanly separates it from add_chart and delete_chart. It stops short of naming those siblings explicitly, so it lands just below the top band.

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?

Gives the crucial partial-update rule ('Only the options you give are changed') and tells the agent where required chart ids originate ('get_spreadsheet_info or add_chart'). No explicit when-not conditions or alternatives are stated, but the context needed to invoke it is clear.

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