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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavior beyond annotations: it discloses that the tool returns exact filter values with open-offer counts and that results can be optionally scoped by a query and town.

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 with no wasted words. The core purpose and return value are front-loaded, followed by the optional scoping parameters.

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 fills an important gap by explaining that the result includes each filter value and its count of open offers. It also covers parameter roles and the relationship to search_offers, leaving only minor details like pagination or result limits unaddressed.

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 the schema already documents all three parameters with their types and descriptions. The description maps the dimension enum values to human-readable labels and mentions query/town scoping, but adds little beyond what the schema provides.

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 states a specific verb (list) and resource (offer filter values / facets for one dimension), and explicitly ties the tool to search_offers. It names the four possible dimensions and says the output includes counts of open offers, making it distinguishable from sibling search and lookup tools.

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 makes clear this tool supplies the exact filter values accepted by search_offers, which implies when to use it. It does not explicitly state when not to use it or name alternatives among the siblings, so it falls short of a full 5.

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