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

Annotations already declare this as read-only, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds a genuine data-quality caveat (benchmark bands are illustrative, not a metro measurement), which is useful context beyond the annotations, though it says nothing about how the calculation handles the many input modes.

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?

Three sentences, fully front-loaded with the core purpose followed by the important caveat. No filler, though the two caveat sentences could be tightened into one without losing meaning.

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 10-parameter computation with almost no schema documentation and no output schema, the description is too thin. It explains the output concept and the benchmark caveat but leaves the agent unable to correctly map or interpret most of the required and optional parameter behavior.

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 only 10% across 10 parameters, so the description carries the burden but fails to compensate. It references EGI (one of the ten) but never explains taxes, insurance, maintenance, mgmt_pct, mgmt_dollars, mgmt_mode, mode, vacancy_pct, or monthly_rent, nor the interplay between mgmt_pct/mgmt_dollars and annual vs monthly modes.

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 produces operating-expense lines as a percent of effective gross income and compares them to national benchmark bands, which distinguishes it from the other calculate_* siblings that handle amortization, cap rate, cash flow, etc. It lacks an explicit verb ('Calculate...'), reading as a noun phrase, but the resource and output are unambiguous.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternative tools. The caveat that the bands are 'illustrative' and 'not a metro measurement' concerns interpretation of results rather than when or how to invoke the tool.

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