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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so 'Read-only' is largely redundant. What the description adds beyond annotations is the permission-scoped visibility ('can see') and the error contract ({error, kind, hint}), which genuinely helps an agent handle failure.

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 short sentences, front-loaded with purpose, then contract, then cross-tool linkage, then errors. Nothing is wasted, and the most decision-relevant fact (what this returns and where it goes) comes early.

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 no-arg discovery tool with annotations and an output schema, this covers purpose, error shape, and downstream usage. Restating the return JSON duplicates the output schema, so it is slightly over-complete rather than missing anything.

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?

Zero parameters, so the baseline is 4; 'Takes no arguments' confirms that explicitly and the workspace id/name linkage explains how this tool's output feeds parameters on other tools. No further parameter meaning is needed.

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 ('Lists the Fabric workspaces') plus an access scope ('the signed-in account can see'), which distinguishes it from data-level siblings like list_sources and list_tables. An agent can tell exactly what this returns without opening the schema.

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 line 'the name or id is the `workspace` of the other tools' implicitly establishes this as the prerequisite discovery call before workspace-scoped tools. It stops short of explicit when-not-to-use guidance or naming an alternative, so it lands at 4 rather than 5.

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