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

Annotations already declare readOnly=true, idempotent=true, openWorld=false, destructive=false, so safety is covered. The description adds genuine context beyond that: alias normalization behavior, the non-authoritative nature of the result ('not official immigration advice'), and conditional linking of place_url. It stops short of describing the response shape, but the output schema exists for that.

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?

Four short sentences, front-loaded with purpose, then naming rules, then the disclaimer. Each line carries usable information with no filler, though the naming-convention sentence and the disclaimer could be tightened.

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 an output schema present, return values need not be explained, and the description covers the key agent-facing caveats: input naming conventions, alias tolerance, non-authoritative status, and conditional URL linking. Adequate for a 4-param, well-documented read tool.

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% and two params are enums, so the schema does the heavy lifting — baseline 3. The description's note about naming conventions and alias normalization is largely redundant with the enum constraints, though it mildly reinforces the format and mentions handle-based linking for destination_handle.

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 ('Check') plus the resource ('visa hassle for a passport country and destination country'), which is unambiguous about what the tool returns. No visa sibling exists among the destinations.*/profile.* tools, so sibling differentiation is not required. The phrasing 'visa hassle' is slightly informal but the required params make the intent obvious.

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?

Offers input-format guidance ('Use visa-table country names... Common aliases are accepted') and a scope caveat ('planning context, not official immigration advice'), which imply when it applies. However, it never states when to reach for this tool versus alternatives or prerequisites (e.g., needing user_visas to be meaningful). Usage is implied rather than explicit.

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