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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=true. The description adds real value on top: 'Replace weekly hours' clarifies it is an overwrite, and 'Existing bookings are kept' scopes exactly what is and isn't destroyed. It does not describe rate limits or auth error behavior, but the annotation bar is already met.

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 with no filler. The auth constraint is front-loaded ahead of the scoping and side-effect information, which is the right ordering.

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 mutation tool with no output schema, it covers the key concerns: who may call it, what scope it applies to, that it overwrites, and that bookings survive. Only detailed return/permission behavior is missing, which is minor given the annotations cover the safety profile.

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 description coverage is 33%, with business_id documented in the schema and the hours sub-fields (days/open/close) well annotated. The description adds meaning for resource_id ('one staff member/room'), compensating for the undocumented parameter, but adds nothing to the already-described fields. A baseline 3 is appropriate.

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: 'Replace weekly hours of the business, or of one staff member/room with resource_id.' This clearly distinguishes the business-wide scope from the per-resource scope. It does not explicitly name the read counterpart owner_get_schedule, so sibling differentiation is implicit rather than stated.

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?

'Only for business owners signed in to Awning' gives a clear auth precondition, and the resource_id clause tells the agent when to target a staff member/room versus the whole business. No explicit when-not guidance or named alternative is provided.

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