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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: the returned fields and the fallback behavior that the first workspace is used when a slug is omitted, which affects how downstream calls behave. Pagination and scoping to the current user are not addressed.

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 tight sentences; the resource description and return fields come first, followed by the cross-tool convention. No filler or repetition.

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 output schema and no parameters, the description carries the burden of explaining what comes back, and it does so by naming the three returned fields. Combined with the workspace-slug fallback note, an agent has everything needed to call this tool correctly and use its result.

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 the baseline is 4. The description's mention of an optional workspace slug applies to sibling tools rather than this one, so it adds context but no parameter detail here.

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 (list the user's Breakreach workspaces) and names the returned fields (slug, name, timezone). This distinguishes it clearly from the many other list_* siblings such as list_accounts and list_posts, which return different resources.

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?

Adds real routing guidance by explaining the workspace-slug convention: most tools take an optional workspace slug and default to the first workspace when omitted, which implicitly tells the agent why and when to call this tool first. It stops short of explicitly naming alternatives or stating when NOT to use it, so it isn't a full 5.

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