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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds meaningful non-annotation behavior: prefix-matching semantics of the returned codes, pagination via offset/limit, and the cost profile ('Free to call; does not consume account balance').

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 purpose, then rules, examples, and cost. It is dense and slightly long, but nearly every sentence carries actionable information and none is redundant with the schema.

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 carries the return-shape burden and does so by specifying string IDs and an example. It also covers the pagination, search, and cost concerns an agent needs before calling.

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 100%, so the baseline is 3, but the description adds real value: it explains the downstream purpose of countryId, gives concrete code examples ('62100' = Computer programming in Finland), and shows search terms and offset stepping that go beyond the schema's field docs.

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 ('List detailed industry codes for a specific country') and immediately scopes it by country classification system. It is clearly distinguishable from siblings like list_industry_groups and list_countries through the classification-system detail.

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?

Explains when to use it (to obtain IDs required for the industryCodes filter on segment tools) and gives a hard rule ('Always pass countryId matching the country you are segmenting'). It stops short of explicitly naming list_industry_groups as the alternative for grouped views, so it's clear context without full alternative routing.

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