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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the mortgage math uses Canadian semi-annual compounding, and the output includes a local-market cap-rate benchmark. It does not discuss error conditions or assumption caveats, but for a stateless calculator this is solid.

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 tight sentences with no filler. The metric list comes first and the Canadian-compounding caveat is placed last as a scoping note, which is the right front-loading.

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?

With no output schema, the description usefully enumerates the returned metrics, and it flags the Canadian-specific calculation convention, which matters for a 9-parameter domain tool. It stops short of explaining required-vs-optional inputs or the benchmark source, leaving minor gaps.

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 78% and most parameters carry their own descriptions (including units and the all-cash downPayment tip). The description only indirectly explains the 'city' parameter via the local-market benchmark sentence, adding little beyond the schema. Baseline 3 is appropriate.

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 ('Analyze') and resource ('a Canadian rental property') and enumerates exactly which metrics are produced (cap rate, NOI, GRM, expense ratio, cash flow, cash-on-cash return). An agent can distinguish it from siblings like mortgage_payment or mortgage_affordability without opening the schema.

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?

Usage is implied by 'Analyze a Canadian rental property' plus the market-benchmark comparison, so an agent can infer this is the investment-return tool rather than a financing tool. However, no explicit when-to-use/when-not guidance or named alternative (e.g. mortgage_payment for pure loan math) is given.

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