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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description adds a genuinely behavioral fact beyond them: the selection is 'remembered across sessions,' i.e. it mutates persistent state rather than being a per-call scoping argument. It stops short of saying how to inspect or clear the current selection.

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 short sentences, zero filler, with the cross-tool scoping effect front-loaded and the persistence note second. Nothing to trim.

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?

An output schema exists, so return values need no explanation. Purpose, single-parameter sourcing, and cross-session persistence are all covered, though interaction with concurrent sessions or how the selection interacts with tools that accept their own workspace argument is unstated.

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?

One parameter with 100% schema description coverage; the schema already tells the agent to supply 'the workspace_id from list_workspaces.' The description adds nothing about the identifier format or source beyond that, so the schema baseline of 3 applies.

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 ('select') and resource ('workspace') and adds the crucial scoping effect: it determines which workspace 'the other tools act in.' That distinguishes it from list_workspaces, which merely enumerates them, so an agent can route correctly without opening either 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 phrase 'which workspace the other tools act in' implies this tool should be called before other operations, which is useful implicit guidance. However, it never states when not to call it, whether it is required, or what happens if it is skipped, and no alternative is named.

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