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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds behavior beyond that by enumerating what the caller receives (address, hours, services, and practical tips for 90-day reports, extensions, TM30), which substitutes for the missing output schema; it does not cover data freshness, multiple offices per city, or result ambiguity.

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 with no filler; the primary purpose comes first and the payload details follow. Every clause contributes information an agent would otherwise lack.

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 inventories the response fields, and it covers both geographic lookup modes. The remaining gap is that all three parameters are optional, yet the description never explains the fallback when no location input is supplied.

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 only 33%: only 'city' is documented, and lat/lng carry no description anywhere. The phrase 'for a Thai city, area or coordinates' hints that city and lat/lng are alternative lookup modes, but it does not say whether they can be combined or what happens when all three optional parameters are omitted.

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 and resource ('Find the immigration office') and adds scope: a Thai city, area or coordinates, plus the returned content (address, hours, services, tips). This clearly separates it from visa-rule siblings like check_visa_eligibility and get_visa_rules, though no sibling is named explicitly.

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 the input modes ('for a Thai city, area or coordinates') and by the mention of 90-day reports, extensions and TM30. However, it never states when to prefer find_providers or list_places instead, and gives no prerequisites or exclusions.

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