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

With no annotations provided, the description carries the full behavioral burden, and 'Read-only, free' usefully discloses the safety profile and cost. However, it says nothing about auth requirements, error behavior, or whether the id must reference an existing audience for the caller, leaving meaningful gaps.

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 short sentences, front-loaded with purpose and capped by the read-only/free qualifier. No filler; every clause earns its place.

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 annotations and no output schema, the description partially compensates by naming the returned filters and contact count. It is adequate for a simple single-record read, but the absence of annotations and any id-format guidance leaves it short of complete.

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 0% and the single 'id' parameter is undocumented. The description hints the id identifies a saved audience, which adds marginal meaning, but does not specify format or source of the id; with only one obvious parameter the gap is modest but real.

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 ('Read one saved audience') and even names the return payload (filters and contact count). The singular 'one saved audience' implicitly distinguishes it from list_audiences, but no sibling is explicitly named, so it stops short of a 5.

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?

Usage is only implied: 'one saved audience' suggests fetching a single record when you already have an id, contrasted with list_audiences. There is no explicit when-to-use/when-not or named alternative, so it is minimum-viable rather than directive.

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