Set Sheet Property

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

Annotations indicate destructiveHint=true and readOnlyHint=false, which the description aligns with by explaining write/update behavior. It adds useful context about hidden creation, in-place updates, and formatting preservation, going beyond the annotations. However, it does not detail potential failure modes or what happens if the sheet is not found.

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 well-structured sentences that front-load the main action and then provide necessary details and exclusions. No redundant wording, every sentence contributes.

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 description covers purpose, identification, behavior, and exclusions, which is sufficient given the detailed annotations and presence of an output schema. It doesn't elaborate on error conditions, but that is a minor gap for a tool with clear schema and annotation support.

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 100%, so the baseline is 3. The description adds value by explaining the matching semantics for sheetName/sheetPath (basename match against file property) and clarifying that key/value represent custom metadata. This goes beyond the schema descriptions.

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 uses specific and actionable language ('Add or update a custom property') and identifies the exact resource ('hierarchical sheet's block'). It distinguishes itself from sibling tools by explicitly excluding built-in 'Sheet name'/'Sheet file' properties and pointing to add/remove_hierarchical_sheet for managing sheet links.

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?

Provides explicit when-to-use context (adding/updating custom sheet metadata) and clearly states what cannot be done (built-in properties) with a directed alternative (use add/remove_hierarchical_sheet). Also clarifies identification via sheetName or sheetPath with basename matching, giving practical usage guidance.

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