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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds the non-obvious eligibility constraint and the downstream consequence of the timezone value for schedule_post. It stops short of describing what happens when no eligible workspace exists or the response ordering/shape beyond the two named fields.

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?

Four sentences, front-loaded with the purpose and output fields, then the family-wide routing rules and the plan gate. No filler or repeated information; each sentence carries distinct decision-relevant content.

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 parameterless discovery tool with no output schema, the description covers purpose, return fields, eligibility, and how the result feeds into other tools. Only minor gaps remain, such as behavior when the list is empty or errors on ineligible plans.

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 high. The description goes further by clarifying semantics of workspaceId for the sibling tools that consume it, which is useful cross-tool context even though this tool itself has no inputs.

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?

Opens with a specific verb+resource ("List the Posteady workspaces you can use") and immediately names the returned fields (workspaceId, timezone). It is clearly distinguishable from sibling list_* tools because it returns workspaces rather than accounts, posts, or media.

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?

Explicitly explains the selection logic for the whole tool family: read tools search all workspaces unless a workspaceId is passed, while write tools infer the workspace from accountIds. It also states the plan gate (CREATOR or higher, eligible: true), so an agent knows both when to call this and what to do with the result.

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