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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=true, openWorldHint=false. The description adds meaningful context on top: the change is label-only and does not touch attributes or data, plus the server-side conflict rejection code. There is mild tension with destructiveHint=true (the old name is overwritten), but this is a scoping claim rather than an outright contradiction.

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 action and scope before the caveat, with no padding. The 'Formia should disambiguate via prose' phrasing is somewhat internal/odd but stays short.

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 simple two-parameter tool with an output schema (so return values need not be explained), the description covers impact scope and the main error mode. Remaining gap: no indication of permission requirements for renaming a shared sheet or validation rules on the new name, and sheetId is undocumented.

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 0% and there are two required parameters. The description adds a little for 'name' (it is a display label subject to conflict), but sheetId is completely unexplained and nothing is said about name length limits (1-120), uniqueness rules, or whether name must be unique per space. It does not compensate for the coverage gap.

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?

Names a specific verb+resource (rename a sheet) and immediately scopes the change ('display label change only'), which implicitly separates it from the attribute-mutating siblings like sheet.add_attribute and sheet.update_attribute. It stops short of naming an alternative tool, so it is clear but not fully sibling-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?

Gives an actionable conditional path for the failure case: if the server returns SHEET_NAME_CONFLICT, disambiguate via prose. That is real usage guidance beyond the happy path. It still does not say when to prefer sheet.rename over other sheet tools, so it is context without explicit alternatives/exclusions.

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