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

With annotations declaring a non-read-only, idempotent, non-destructive mutation, the description adds useful behavioral context by clarifying that omitted settings are preserved. It does not restate idempotency or concurrency behavior, but the idempotencyKey schema description covers that gap and the annotations already establish the safety profile.

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 tightly written sentences with the primary action and scope front-loaded, followed immediately by the alternative for data type changes. Every clause contributes to selecting or correctly using the tool.

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?

The output schema and annotations reduce the description's burden, and it successfully covers the partial-update semantics and one alternative. However, for a five-parameter mutation with an unexplained required concurrency parameter and no clarification against sheets_rename_column, the description is only minimally 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?

Schema description coverage is only 20%, so the description must compensate for undocumented parameters but largely does not. It enumerates the changeable fields in the changes array, matching schema const values, yet it never explains required parameters such as expectedColumnVersion or the optimistic-concurrency requirement, leaving significant parameter meaning unstated.

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 verb, resource, and scope: partially change a column's name, prompt, format instructions, or context-column scope without resetting omitted settings. It also explicitly distinguishes itself from sheets_change_column_type for data type changes, allowing an agent to select it without opening the schema.

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 a clear usage context (partial update without resetting omitted fields) and names one alternative, sheets_change_column_type, with the condition that selects it. However, it does not mention how it differs from the sibling sheets_rename_column, which also appears relevant when changing a column name.

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