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

Annotations already flag destructiveHint=true and openWorldHint=true; the description adds genuine value on top by disclosing the dry-run/confirmation gate, the no-write behavior when confirmation is withheld, format normalization to two decimals, and validation-error returns. It omits rate limits and any note on reversibility or downstream effects on live pacing.

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?

Four sentences, front-loaded with the action, then the confirmation rule, then value formatting, then return behavior. Every sentence carries operational information, though the final sentence about return values is the least essential given it restates the obvious success/error dichotomy.

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, open-world mutation with a nested-object parameter and no output schema, the description covers the confirmation mechanism, value coercion, and error surfacing, which is most of what an agent needs. Missing only edge-case behavior such as invalid or unknown experiment IDs mid-batch and whether partial updates occur.

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 the baseline is 3; the description still earns more by stating that values accept numbers or decimal strings with dot or comma and are normalized to two decimals, and by framing the amounts as exact impact values rather than a pool to be redistributed. The dictionary-of-experiment-IDs structure is left to the schema's example.

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?

Opens with a specific verb and resource (update daily budgets for specified experiment IDs) and clarifies a non-obvious scope point: live experiments are included, which separates it from read-only or draft-only experiment tools. It never names a sibling (e.g. update_experiment_end_date or manage_experiment) to sharpen the boundary, so it stops short of a 5.

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 concrete operating guidance: exact amounts require confirm_budget_impact=true, and otherwise the call returns requires_confirmation and proposed_changes without writing. That effectively documents the two-step safe invocation pattern an agent must follow. It does not explicitly say when to prefer this over sibling budget tools such as create_budget_group or manage_experiment.

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