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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the data is researched, limited to five countries, and each record carries a source URL and a last-checked date, which tells the agent about freshness and provenance.

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?

Front-loaded with the core purpose and coverage, then the returned fields, then a compact Args block. Every sentence carries information, though the Args section restates parameter names in a slightly verbose docstring style.

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?

An output schema exists, so return values need not be enumerated, yet the description still names the key fields (income threshold, fees, processing time, years to PR/citizenship, source URL, last checked). Combined with the country coverage list and parameter semantics, an agent has everything needed 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 0%, so the description must carry the load, and it does: country is documented as an ISO alpha-2 code or English name with examples ('es' or 'Spain'), and category enumerates the three valid values ('digitalNomad', 'passiveIncome', 'work') that the schema does not constrain. It stops short of stating that both are optional filters and what the unfiltered default returns.

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+resource ('Residence visas GoThere has researched') and immediately scopes it to Americans moving abroad plus the five covered countries. An agent can tell this apart from siblings like list_pathways or get_pathway_requirements because it is explicitly a researched-options lookup with per-option data fields.

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 only implied: the country/category args suggest filtering, but the description never says when to call this versus list_pathways or get_pathway_requirements, nor what happens when a country is not covered. No exclusions or prerequisites are given.

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