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

Annotations already declare readOnlyHint/idempotentHint/non-destructive, so the safety profile is covered. The description adds genuinely valuable behavioral context beyond that: this is a formula estimate rather than the bank's actual schedule, stage 2 rate depends on the bank's accumulated score, the 20% state premium and deposit term, and loan limits vary by region.

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 core content is front-loaded and dense with useful specifics (program durations, rate band, regional limits). The trilingual keyword header ('Otbasy mortgage estimate / ипотека Отбасы банк / Отбасы банк ипотекасы') is redundant padding, but every subsequent sentence carries real information.

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 and 7 parameters, the description carries the burden of describing results — and it does list the computed outputs (deposit/down-payment/limit checks, stage 1 monthly payment, stage 2 range). It stops short of enumerating exact return fields or units, but covers the calculation's structure well enough to call it correctly.

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 baseline is 3. The description adds some interpretive value by explaining that the stage 2 rate (3.5%–5.0%) is not an input because it depends on the bank's score, and by restating that limits hinge on region — but it does not give per-parameter meaning beyond the already-exhaustive 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?

The description opens with a concrete verb+resource ('Estimates the two-stage housing loan of Otbasy Bank under the "Nauryz" and "Otau" programs') and enumerates exactly what is computed: deposit/down-payment/limit checks, stage 1 monthly payment, and stage 2 payment range. It is unmistakably distinct from the sibling tools, which cover taxes, salaries, benefits and fines.

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 context is implied ('It is a formula estimate, not the bank's schedule'), which tells the agent this is an approximation rather than an authoritative schedule. However, there is no explicit when-to-use/when-not-to-use statement and no alternative tool is named or excluded, so the agent must infer the applicability window.

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