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

Without annotations, the description carries the full burden of behavioral disclosure. It discloses the return fields (name, mode, creation date) and explains the workspace-surface model, which is useful context for interpreting results. It also mentions 'authenticated principal,' implying an auth requirement. It does not cover pagination or ordering, but for a simple list tool this is a minor gap. Overall, it provides solid transparency.

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?

The description is composed of three sentences. The first sentence states the core purpose, the second lists the return fields, and the third provides conceptual context and an alternative. Each sentence contributes useful information, but the third sentence is a bit lengthy and could be split or simplified. Still, it is well-organized and front-loaded, earning a 4 rather than a 5.

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?

Given the tool's simplicity (no parameters, no output schema), the description is remarkably complete. It explains what the tool does, what it returns, the underlying domain model (workspaces contain surfaces), and provides an alternative for deeper exploration. There are no significant missing pieces for an agent to invoke this tool correctly.

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 has zero parameters, so the baseline is 4. The description doesn't need to explain parameters but adds value by describing the return fields and their meaning (e.g., 'mode (the default-view preference for the first tab)'). This helps the agent understand the output, though it is not strictly required for parameter semantics.

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?

The description clearly states the tool's purpose: 'List all workspaces the authenticated principal has access to.' It uses a specific verb ('List') and resource ('workspaces'), and distinguishes itself from the sibling tool 'list_surfaces' by explicitly noting that 'list_surfaces' is for viewing what a workspace contains.

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?

The description includes an explicit alternative: 'Use list_surfaces to see what a given workspace actually contains.' This provides clear guidance for when to use this tool versus a specific sibling. It also gives contextual information about workspaces and surfaces, helping the agent understand the domain. However, it does not exhaustively discuss all possible alternatives (e.g., get_workspace for detailed info on a single workspace), so it falls short of a 5.

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