List popular genres

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds genuinely new behavioral context: results are ordered by count of working stations and placeholder/non-genre tags (country, region, language, 'radio', 'fm') are filtered out, which an agent could not infer from the schema.

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: purpose first, behavioral filtering second, routing guidance last. No filler, every sentence carries information an agent needs.

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?

A low-complexity, single-parameter read tool with full annotations and an output schema; the description covers purpose, filtering behavior, ordering, and the chaining target, leaving nothing material unexplained.

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% and the single limit parameter is fully documented in the schema (1-100, default 30). The description adds no further syntax or semantics for it, so the baseline 3 applies.

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 (List) and resource (genre/format tags in the Radio Browser directory) plus the ranking criterion (by number of working stations). The explicit filtering note distinguishes it from siblings like list_countries, which return the very country/region names this tool strips out.

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 explicit downstream usage — feed a returned name into search_stations or top_stations as the tag argument — which is strong contextual guidance. It stops short of stating when NOT to use it (e.g., use list_countries for country facets), so it is clear context without exclusions.

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