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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. Beyond that, the description adds genuinely useful behavior: results are capped at 100 and returned most-popular-first, and it notes the constraints are enforced by the API rather than the wrapper.

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 tight sentences with the scope and output shape front-loaded, followed by the parameter constraints. It repeats the 'at least 3 characters' constraint that already lives in the schema and appends a bare 'GET /locations', minor redundancy but no wasted structure.

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-value burden and does so by naming the returned fields, their ordering, and the 100-result cap. Safety is covered by annotations. Only edge behavior (empty results, whether the cap implies truncation or pagination) is left unstated.

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 both parameters (free-text search with minLength 3, ISO alpha-2 country pattern) are already fully documented in the schema. The description restates the ISO letter-code and 3-character minimum without adding format or example detail beyond it, so the baseline of 3 is appropriate.

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 ('Search the locations Wincher can track rankings for'), names the returned fields (code, name, country), and describes ordering and result cap. An agent can distinguish this from the nearest sibling (wincher_list_search_engines) without opening either schema.

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 states both inputs are required by the API and that search needs at least 3 characters, which implies the tool is a lookup prerequisite to setting up ranking tracking. However, it never says when to prefer this tool over alternatives or what to do when the search yields nothing, so usage is implied rather than guided.

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