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

Annotations only declare the mutation-safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false). The description supplies the genuinely important behavior the annotations cannot: the selection is stateful and persists across later calls and messages until changed, and it re-scopes drafts, schedules, channels and analytics. That is exactly the hidden side effect an agent must know before calling.

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?

Front-loads the action, then consequences, then the usage rule and the exclusion. Four compact sentences, each carrying a distinct piece of decision-relevant information with no 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?

Single-parameter stateful tool with no output schema; the description covers what changes, how long it lasts, and the main misuse case. Nothing an agent needs in order to invoke it correctly is missing.

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?

Schema coverage is 100% and the schema already documents the single 'workspace' parameter, including accepted forms (name or numeric id) and the source ('as returned by list_workspaces'). The description adds nothing about the parameter, so the baseline 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 and resource ('Switch which workspace (client) you are working in') and immediately clarifies the scope of the change. An agent can distinguish it from draft_post and select_account without opening any 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?

Gives explicit trigger phrases ('switch to Acme', 'work on Acme now'), an explicit exclusion ('Do NOT use it to write something FOR a client while staying where you are'), and names the correct alternative (draft_post with the topic). This is the when/when-not/alternative trifecta.

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