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

Annotations already declare readOnlyHint and idempotentHint, covering the safety profile. The description adds the specific checks performed, which is useful beyond annotations, but it does not disclose limitations such as not verifying account existence or the exact semantics of the country-alignment logic.

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, front-loaded sentence that concisely enumerates the tool's scope without any fluff. Every word contributes to understanding what the tool does.

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?

Given the low complexity (3 parameters, 1 required, output schema present, read-only/idempotent annotations), the description sufficiently covers the tool's scope. It lacks explicit guidance on alternatives, but that is already accounted for in usage_guidelines, and the remaining context is adequate for invocation.

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 parameters are already documented. The description's mention of IBAN checksum, country alignment, and pre-viewing flag maps to the parameters but adds no extra format, constraints, or relationships 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?

The description specifies a concrete domain (rental deposits) and enumerates three distinct checks: IBAN checksum, property/deposit country alignment, and pre-viewing flag. This distinguishes it from generic iban_check and other siblings, though it lacks an explicit verb such as 'validates' or 'assesses'.

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?

The title and description imply use in rental deposit scenarios, providing enough context to infer when to call this tool. However, there is no explicit guidance on when to prefer it over iban_check or rental_verdict, and no exclusions or alternatives are mentioned.

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