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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It does state that it uses sourced CRA/provincial rates and is a planning estimate, which is helpful. However, it does not explain calculation assumptions (e.g., how expenses are netted against revenue, what tax credits are included, CPP exemption thresholds). For a financial calculation tool, this is a notable gap.

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 description is concise and front-loaded. The first sentence states the core purpose, followed by relevant details about data sources and supported provinces. Every sentence earns its place, with no redundant information; the province list is compact and necessary.

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?

The tool has no output schema, so the description should clarify what the response contains. It says it estimates tax, CPP, and take-home, but does not specify whether this is a breakdown, a single value, or a formatted report. Additionally, it does not mention edge cases like default expenses (though the schema covers this). The description is adequate but incomplete for a financial planning tool.

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 schema has 100% parameter coverage, giving clear definitions for revenue, expenses, and province. The description adds meaningful value by listing all valid province slugs and excluding Quebec, which goes beyond the schema's 'e.g.' examples. This compensates for the lack of enums in the schema.

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 clearly states the tool's function: estimating 2026 income tax, CPP, and take-home for self-employed Canadian contractors/sole proprietors by province. It is specific about the verb ('estimate'), the resource (tax, CPP, take-home), and the target audience, and it naturally distinguishes itself from sibling tools like hst_quick_method or required_hourly_rate by focusing on income tax estimation.

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 provides clear context: it is for self-employed contractors/tradespeople, covers a list of provinces, and explicitly excludes Quebec. It also includes a 'planning estimate, not tax advice' disclaimer, which guides appropriate use. However, it does not explicitly name alternative tools to use instead for other scenarios (e.g., HST estimation), so it falls short of a 5.

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