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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The word 'starting' hints the output is a heuristic recommendation, but the description adds essentially no behavioral context and spends its second sentence on a promotional URL rather than useful detail.

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 first sentence is tight and front-loaded. The second sentence is a bare link to an external calculator page, which is promotional rather than functional and does not earn its place in a tool definition.

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 simple two-parameter calculator with no output schema, the description conveys the core purpose but says nothing about the shape of the returned split (percentages vs. dollar amounts), currency assumptions, or how 'starting' recommendations should be interpreted.

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?

The description restates the two schema parameters (total budget, average contract value) without adding unit, currency, or format detail beyond the 100%-covered schema. Baseline 3 is appropriate since the schema already documents both inputs.

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 (suggest) and resource (Google/Meta/LinkedIn budget split) plus the two driving inputs. An agent can distinguish it from brand_vs_performance_budget_allocator or ad_spend_waste_calculator, though the description never names a sibling to sharpen that contrast.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives among the many adjacent budget tools. An agent must infer the use case purely from the name and inputs.

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