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

Annotations already declare readOnly=false, destructive=false, idempotent=false and openWorld=false, so the safety profile is covered. The description adds the return hint ('Returns the sheet and a link to open it') and the workspace scope, but says nothing about permissions, side effects, or whether creating is reversible in this tool's own terms.

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 purposeful clauses: trigger, output, and routing alternative. Front-loaded with the trigger and zero 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?

With an output schema present, return values need no elaboration, and annotations carry the safety profile; the description covers purpose, trigger, and the nearest alternative. Only marginally thin on creation-time behavior, but complete for correct invocation.

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 both parameters (brief, title) are already documented in the schema. The phrase 'with formulas where useful' mildly informs what the brief should contain, but adds little beyond structured data, so baseline 3 applies.

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?

Specific verb (create) plus resource (spreadsheet/data table) with concrete examples (budget, tracker, schedule, list). It also explicitly distinguishes itself from the add_rows sibling, so an agent can route without opening either 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?

The opener gives an explicit trigger ('when the user wants a new spreadsheet...') and the closing sentence names the alternative and the condition that selects it ('To add rows to an existing sheet, use add_rows'). Nothing is left to inference.

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