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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context: a `full_access` API key is required and the call maps to POST /audiences (operationId createAudience). It could still note duplicate-name behavior implied by idempotentHint=false.

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 the action, with the endpoint metadata compactly appended. Nothing is padded, though the operationId/parenthetical is closer to internal bookkeeping than agent-facing guidance.

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 one-parameter create tool with full annotation coverage and no output schema, the definition is close to sufficient. It still omits what an audience is in this system, whether names must be unique, and whether anything is returned on success.

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?

There is exactly one parameter (`name`) with 0% schema description coverage, and the description never mentions it or its constraints (1-100 chars). It should at least state that `name` is the audience label and whether uniqueness is enforced, since the schema supplies only type and length.

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 ('Create an audience'), which cleanly separates it from get_audience, list_audiences, delete_audience and update_* siblings. It does not explicitly contrast itself with any sibling, but the CRUD naming makes the role unambiguous.

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?

No guidance on when to create versus using an existing audience, no prerequisites beyond the API key tier, and no mention of how it relates to create_contact/create_broadcast workflows. The agent must infer usage entirely from the name.

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