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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description's added value is the behavioral detail that the dashboard is created empty and appears as a Charts view, which prevents the agent from expecting auto-generated charts. It does not mention permission requirements or whether creating a dashboard renames or reorders anything, so it stops short of 5.

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, front-loaded with the core action, with each sentence carrying distinct routing or behavioral information. No filler or restatement of the name/title.

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?

An output schema exists, so return values need not be explained, and the description covers what is created, what it looks like, and what to do next. The remaining gap is the undocumented optional parameters (icon, description) and any precondition on permissions for the target sheet, which an agent would have to infer.

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 50% — 'name' and 'description' have no schema-level descriptions at all, and the tool description adds no meaning for them (no hint about defaults, uniqueness, or how description is surfaced). The only parameter context given ('to a sheet') merely restates what the schema already says for sheetId. With half the parameters undocumented on both sides, the description fails to compensate.

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 ('Add an empty dashboard to a sheet') plus the observable outcome ('it shows as a Charts view'). It also names the sibling used for the follow-up step (widget.create) and the alternative entry point (steps.draft), so an agent can distinguish it from sheet.create or widget.create without opening a 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?

Explicitly sequences usage ('Then add charts and numbers with widget.create') and routes the agent away from this tool when the goal is a sheet plus its dashboards ('use steps.draft instead'). It lacks an explicit negative condition (e.g., when you already have a dashboard, use dashboard.update), which keeps it just short of the top mark.

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