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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states 'Read-only' and that browsing is free (no credit cost), which are critical safety and cost behaviors. It does not detail return structure or pagination, but for a simple list tool the key side-effect information is present.

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 precise sentences: the first front-loads the action and scope, the second adds cost and safety clarifiers. There is no filler, repetition of the tool name, or redundant information.

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 zero-parameter, read-only marketplace listing with no output schema, the description covers what the tool does, what it returns (audiences and categories), and its safety/cost profile. Nothing essential for correct invocation is missing.

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 input schema is empty with zero parameters, so the baseline is 4. The description adds no parameter specifics because none exist, but it clarifies that the output includes audiences and their categories, which is the only relevant semantic information.

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 action ('Browse') and resource ('pre-built, ready-to-use audiences available for purchase'), and notes that categories are included. It clearly separates this tool from buy_audience_set by emphasizing browsing over purchasing, and from list_audiences by the marketplace scope.

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 phrase 'Browsing is free; buying costs credits' establishes that this tool is for non-destructive browsing and implies purchase actions belong elsewhere, such as buy_audience_set. It does not explicitly name the alternative tool or provide a when-not condition beyond cost, so it falls short of fully explicit routing guidance.

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