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

With no annotations, the description carries the full burden and does fairly well: it discloses the year scope (2026), the supported province set, the Quebec-specific CRA/Revenu Québec remittance split, and the three computed outputs. It never states that this is a side-effect-free calculation or describes error behavior for invalid inputs, which is the remaining gap for a no-annotation tool.

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?

A single dense paragraph that front-loads the core action ('Invert payroll for 2026') before the use case, the competitor caveat, and the province list. Every clause contributes scope or output information, though the province enumeration in the schema's own enum makes that final sentence partly redundant.

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 three-parameter calculation tool with no output schema and no annotations, the description covers inputs, output set, audience, year, and geographic scope adequately. It does not describe the shape or units of the returned gross/cost/remittance figures, which would be the natural next detail given there is no output schema.

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%, so all three parameters are already documented in the schema, which sets the baseline at 3. The description adds modest interpretive value by framing target_net_pay as the agreed take-home ('$800/week in their pocket') and by noting that Quebec requires a different remittance split, but it adds no format or boundary detail beyond 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?

States a specific verb and resource (invert payroll from net to gross) and enumerates the three outputs: gross salary, employer total cost, and source-deduction remittances. It is clearly the inverse-direction tool, but it never names or contrasts itself with the siblings employee_take_home and employer_total_cost, and its claim to also return 'the employer's true total cost' overlaps with employer_total_cost, leaving the agent to infer which to pick.

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 a concrete use context ('household employers (nanny payroll) who agree on take-home pay') and names an alternative, CRA's PDOC, along with the condition that disqualifies it (PDOC computes gross→net and does not cover Quebec). It stops short of any explicit when-not-to-use guidance relative to its sibling tools.

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