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

With no annotations provided, the description carries the transparency burden. It discloses that it accounts for 2026 income tax, CPP, province, and billable time, and frames the output as a 'Planning estimate,' indicating approximation. However, it does not mention assumptions, output format, or limitations such as ignoring other deductions or using default values.

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 extremely concise: two sentences that front-load the primary purpose and include a clear qualifier ('Planning estimate'). Every word earns its place, with no redundant information or extended explanations.

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 description covers the core purpose and key inputs, but with no output schema and sparse annotations, it lacks details on return values, default behaviors (e.g., weeks_per_year default 48), or edge cases. For a 5-parameter tool, the description is adequate but leaves notable gaps in behavioral context.

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% with each parameter having a description in the input schema. The tool description adds limited semantic value beyond the schema by referring to 'billable time' and 'take-home,' but it does not detail parameter relationships or syntax. Baseline 3 is appropriate since the schema fully documents individual parameters.

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: 'Work backwards from the annual take-home a contractor wants to the hourly rate they must bill.' This uses a specific verb ('work backwards') and resource (hourly rate), distinguishing it from the sibling 'estimate_contractor_tax' by its directionality. However, it does not explicitly name alternative tools.

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 an implied usage context with 'Planning estimate,' suggesting use for planning rather than exact tax filing. It does not explicitly state when to use this tool versus alternatives, nor does it list exclusions or prerequisites. The context is clear enough for a user to infer, but no explicit guidance is given.

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