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

No annotations are provided, so the description carries the burden. It does add real behavioral context — that the operation is reversible and consumes no credits — which is valuable for a mutation tool, but it omits permission requirements, failure modes, and whether the new name must be unique.

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 with no waste. The core action is front-loaded, though the fragment style ('Reversible, no credits') is terse rather than structured.

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 simple two-parameter rename with no output schema, the description covers the essentials plus reversibility and cost. However, with no annotations and half the parameters undocumented, it leaves the agent without enough behavioral or parameter detail to call it confidently.

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?

Two required parameters with only 50% schema description coverage; the 'name' parameter has no description in the schema. The tool description says nothing about either parameter, so it does not compensate for the gap — an agent gets no guidance on the ID format or naming constraints.

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 (rename) and resource (custom audience), matching the title. An agent can distinguish it from the many sibling audience tools like update_custom_audience_contact or create_custom_audience, though it doesn't explicitly contrast with them.

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?

Provides no when-to-use guidance, no prerequisites, and names no alternatives. The agent must infer that this is the tool for changing only an audience's name versus other update operations.

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