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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds real behavioral detail beyond that: a hard cap of 50 results per call, the next_skip chaining convention, OData query support, and the underlying endpoint. Return format is not described, but for a read-only list tool that is a minor gap.

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?

Three short sentences, front-loaded with the purpose and followed by the two constraints an agent actually needs (page cap and page chaining). No filler, no repetition of the title.

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 should hint at return shape: it does so minimally ('with their codes') and it fully explains pagination, which is the main failure mode for a paged list tool. It does not describe what a next_skip token looks like or whether filtering on country fields is constrained, but nothing essential to a correct call is missing.

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 five parameters are already documented with examples, ranges and defaults. The description restates the paging and OData semantics without adding syntax, format or edge-case meaning beyond the schema, which matches the baseline for full-coverage schemas.

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 ('List countries with their codes') and is trivially distinguishable from the sibling list tools, which cover contacts, organizations, teams, industries, etc. Nothing ambiguously overlaps another tool.

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 description gives operational guidance (paging, page size, chaining) but never states when to use this tool versus alternatives or any prerequisites. For a simple reference-data lookup with no near-duplicate sibling, usage is implied rather than stated.

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