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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint=false), and the description usefully adds that sources are external providers and that new connections happen outside tooling via browser sign-in. It could add more about return ordering/shape, but it adds real context beyond the annotations.

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?

Three tight sentences, each earning its place: the list action, the definition of a source, and the down-stream usage plus the boundary about connecting. Purpose is front-loaded with no filler.

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, no-output-schema list tool with annotations covering the safety profile, the description supplies everything an agent needs: what is returned, where the ids are consumed, and why no connect operation appears in the toolset.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for a parameterless tool is 4. No param semantics are missing.

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+resource ('List the connected verified-audience sources') and immediately defines what a source is (Discord, YouTube, Twitch, Steam providers that a project can gate audience on). This clearly separates it from siblings like disconnect_source and open_project.

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?

Explains the downstream purpose: the returned ids go in `delivery.audience.verified_source_ids` when opening a project, and notes that connecting a new source requires browser sign-in so no such tool exists here. It gives clear context but never names a sibling (e.g., disconnect_source) for the removal case.

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