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

Annotations indicate this is a non-readonly, non-destructive mutation. The description's verb 'assign' aligns with a write operation, but it does not disclose potential side effects (e.g., replacing existing assignments) or permission requirements.

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 concise sentences: first states purpose, second provides a crucial parameter hint. No unnecessary words, front-loaded.

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 simple assignment tool with an output schema and low parameter count, the description covers the essential: what it does and how to supply the userId. Could mention potential overwrite behavior, but not critical.

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?

With 100% schema coverage, the description adds value by clarifying that userId should come from 'list_staff.userId', providing a meaningful cross-reference. ServiceId is less elaborated, but schema description suffices.

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?

Description clearly states the action ('Assign a staff member to a booking service') and identifies the resource. It provides a specific hint on obtaining the userId from list_staff, but does not explicitly differentiate from sibling tools like 'link_resource_to_service'.

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 implies usage by instructing to pass the userId from list_staff, suggesting a prerequisite call. However, it does not provide explicit guidance on when to use this tool versus alternatives or what to avoid.

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