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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false. The description adds non-obvious calculation behavior: assessed value not purchase price, Ontario's 2016 MPAC values, and rates normalised to full assessed value for SK and Winnipeg.

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?

Two dense sentences, front-loaded with what is calculated and the critical assessed-value distinction. The parentheticals earn their place by preventing assessed-versus-purchase-price and rate-normalisation errors.

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 read-only calculator with four fully documented parameters and no output schema, the description supplies enough basis, coverage, override and normalisation context. Remaining schema-level details such as includeQuebecSchoolTax are covered by the parameter descriptions.

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%, so the schema already documents each parameter. The description still adds meaning for assessedValue and ratePct by warning against purchase price and explaining that ratePct overrides the city rate and that published rates are normalised.

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 action and resource: annual and monthly property tax from assessed value for 18 Canadian cities. It explicitly distinguishes assessed value from purchase price, so an agent can identify it among tax and calculator siblings.

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?

It gives a clear usage alternative: pass ratePct instead of city to use the rate on your own bill. It does not explicitly say when not to use this tool versus sibling calculators, but the parameter-selection guidance is concrete.

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