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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description's contribution is disclosing the returned data shape (settings plus three count types), which is genuinely useful since no output schema exists, but it says nothing about permissions, not-found behavior, or whether counts are live.

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?

A single well-formed sentence that front-loads the verb and resource and spends its remainder on return-value detail rather than filler. Nothing extraneous.

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 read-only getter with rich annotations, this covers purpose and return contents adequately. The remaining gaps—not-found/error behavior and whether the counts are real-time—are modest for this tool class.

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?

With 100% schema description coverage and a single 'id' parameter documented as 'Audience ID.', the schema carries the parameter semantics. The description adds no format, ID-source, or lookup guidance beyond what the schema already says.

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 (Retrieve) and resource (audience) and enumerates what the response contains (settings, subscriber/unengaged/pending double opt-in counts). It is clearly distinguishable from mutation siblings like update-audience or delete-audience, though it doesn't explicitly contrast with list-audiences or get-audience-subscriber.

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 by the singular 'get' + required id, i.e. fetch one known audience by ID. There is no explicit statement of when to prefer this over list-audiences or get-audience-subscriber, and no prerequisites or exclusion notes.

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