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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces this with 'It changes nothing' plus the explicit two-step apply path through campaigns and update_budget. It also discloses that increases need user confirmation and that Go Shift never pauses ads automatically, which is genuine safety context beyond the annotations. It doesn't cover rate limits, auth requirements, or error behavior, so it is not a full behavioral disclosure.

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?

The purpose is front-loaded in the first sentence, and each subsequent sentence adds the read-only guarantee, the apply workflow, and the no-auto-pause guarantee. The 'Budget Guard:' brand prefix and the trailing Go Shift safety note are slightly tangential, but nothing is redundant enough to obscure the core instruction.

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 two-parameter, read-only planning tool with no output schema, the description conveys what the result contains (a total daily spend figure and a per-account proportional split) and how to act on it. It lacks detail on the exact response structure and on how the remaining-period calculation handles edge cases like zero recent spend, which keeps it below a 5.

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 100%, with both folder and language documented inline including the enum values, so the schema carries parameter meaning. The description adds nothing about how folder scoping affects the split across accounts or how language shapes the response. Baseline 3 applies when the schema does the heavy lifting.

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 computation and its output shape: total daily spend that keeps a client within budget for the remaining period, split across the client's ad accounts proportional to recent spend. That is a clear verb+resource for a planning tool. It does not explicitly differentiate itself from sibling tools like google_ads_budget_plan, budget_status, or budgets_at_risk, so the agent must infer the client-level vs platform-level distinction.

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 clear downstream workflow guidance: read each account's campaigns with the campaigns tool, then propose new daily budgets via update_budget, with increases requiring user confirmation. This tells the agent what to do after the call. It stops short of stating when this tool should be chosen over budget_status or budgets_at_risk, leaving that selection to inference.

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