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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds the scope of the calculation (fraud + tracking/attribution leakage) but says nothing about output shape or that it is a purely deterministic arithmetic estimate.

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 a tight, front-loaded purpose statement. The second sentence is a promotional link to an external calculator site and does not help an agent decide or invoke the tool, so it does not earn its place.

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 stateless 3-param calculator with no output schema and covering annotations, the definition is adequate but thin: it never indicates the form of the result (a currency amount of wasted spend) or its deterministic, side-effect-free nature beyond what annotations imply.

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% and all three parameters (monthlySpend, fraudPct, leakagePct) are documented in the schema itself. The description adds no extra meaning, so 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?

The description states a specific verb and resource: estimating monthly ad budget lost to fraud and tracking/attribution waste. It is clearly distinct from most siblings (e.g. roas_calculator, competitor_ad_spend_benchmarker) by naming the two loss sources. It stops short of explicitly differentiating itself from near-neighbors such as cpa_to_cac_scalability_matrix.

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 statement of when to use this tool, when not to, or what alternative to pick if the user wants ROAS or CPM-style analysis. Usage can only be inferred from the name and description's subject.

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