List available filters

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

Annotations already cover the safety profile (readOnly, closed world), and the description adds real behavioral value: only values with at least one manufacturer are returned, and counts are included. It stops short of describing the response structure (e.g., how facets and counts are keyed), which matters because there is no output 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?

Two sentences, zero filler. The facet enumeration comes first as the core of the purpose, and the actionable 'call this before filtering' instruction is placed last so it is read immediately before deciding to invoke.

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 parameterless read tool with annotations and no output schema, the description covers what is returned (facet values plus counts) and the important empty-value exclusion. A little more on result shape would close the remaining gap left by the absent output schema.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline of 4 applies; no parameter guidance is needed or possible.

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 enumerates exactly which facet dimensions are returned — countries, categories, certifications, product types, design inputs, industries, MOQ bands. This is clearly distinct from search_manufacturers or get_manufacturer, which return entity data rather than facet enumerations.

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?

Gives an explicit sequencing instruction: 'Call this before filtering so you only use values that exist.' That is a concrete when-to-use cue. It does not name a when-not case or any alternative, which is a minor gap given no sibling offers facet enumeration.

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