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

Annotations already flag destructiveHint=true and readOnlyHint=false, but the description adds real value beyond that: '[WRITE — changes your live account]' and 'Affects every campaign sharing that budget' disclose the blast radius, which is not in the annotations, and it states the confirm:true safety gate. It still omits reversibility and expected response, keeping it short of a 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 clauses, front-loaded with the write/live-account warning, then the scope, then the gate. Zero wasted words.

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 destructive mutation with no output schema, the description covers the critical agent-facing facts: write nature, budget-sharing impact, and the confirm requirement. It is nearly complete, though it does not say what is returned or how a change could be reverted.

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 all four parameters are already documented including the MICROS example and the confirm gate. The description only echoes the MICROS unit and confirm requirement, adding no meaning beyond the schema – the 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?

States a specific verb and resource ('Change a campaign budget's daily amount') and scopes it to budgets rather than campaigns. It does not explicitly name google_ads_update_campaign as the sibling that handles other campaign settings, so the differentiation is implicit rather than stated.

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 description implies usage (a live write with a confirm gate) and the schema points to google_ads_get_campaign for finding the budget id. But there is no explicit when-to-use-this-vs-update_campaign guidance and no stated exclusions or prerequisites beyond the confirm flag.

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