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

With zero annotations, the description carries the full burden, and it does disclose two non-obvious traits: a 100-item page cap and that charges/authorization come from the caller's OpenAny gateway credentials. It does not state whether the operation mutates anything (it is a POST-named search), whether name matching is exact or prefix (only the schema says whole-words-only), or how paging terminates.

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?

Two short sentences, result scope front-loaded, zero filler or restatement of the tool name. Everything present earns its place.

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?

For a one-parameter search with full schema coverage and no output schema, the description covers the essentials an agent needs (what it searches, result cap, credential/billing model). The only real gap is what a returned country record contains, which is minor for a simple geo lookup.

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 the schema is unusually rich ('WHOLE WORDS ONLY', live-verified examples, omit-query-to-page-through-all). The description adds only the page-size detail ('up to 100 countries per page'), so it neither adds nor detracts much beyond the schema baseline of 3.

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?

The description gives a specific verb and resource ('Searches countries by name') plus a scope limit ('returns up to 100 countries per page'), which is far more informative than the bare title. It does not explicitly contrast with the sibling 'treg_get_call_companyenrich_geo_country_get' (single-country lookup) or geo_cities/geo_states search, but the distinction is largely inferable from the verb.

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: an agent can infer this is the lookup path when it has a country name rather than an identifier. There is no explicit when-to-use, when-not-to-use, or named alternative (e.g. the single-country get sibling), and the useful 'omit query to page through every country' guidance lives in the schema rather than the description.

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