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

Annotations establish mutation (readOnlyHint=false) and idempotency, but the description adds substantial behavior beyond them: the switch is session-scoped and does not affect other agents/chats, a new session resets to the key owner's business, and in-flight writes are kept with persist_database confirming durability. This is exactly the extra context annotations cannot carry.

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-loaded with the core action, then scoping, prerequisites, the parameter constraint, and durability notes in order of importance. Dense but every sentence earns its place; the azquo_skills cross-reference is the only slightly cryptic element.

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 session-state mutation tool with no output schema, the description covers everything an agent needs: session scope, credential reachability, the one-of parameter rule, and write-persistence semantics. Nothing material 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% so baseline is 3, but the description adds a genuinely useful constraint absent from the schema: 'Provide exactly one of businessName, businessId, or userId.' The schema marks all three optional with no oneOf/exclusive constraint, so this XOR guidance materially clarifies invocation.

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+resource ('Switch the active business') and precisely scopes it to 'subsequent MCP tool calls in this session,' distinguishing it from the read-only sibling current_business without needing to open 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?

Gives a clear prerequisite and routing hint: 'Target must be one the current bearer can reach — call list_businesses first if unsure.' This tells the agent when this tool is usable and which sibling to consult first, though it does not explicitly contrast with current_business or describe when not to switch.

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