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

Annotations already declare non-read-only, non-destructive, closed-world. The description adds the useful behavior that the saved record is returned with its SyncToken (needed for subsequent updates), but it doesn't mention required permissions, validation behavior, or duplicate handling – beyond safe to add, the record lifecycle is not described.

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, front-loaded with the action and resource, with no filler. Every part earns its place.

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 create tool with no output schema, the return-value note is helpful, but the description does not compensate for missing mutation guidance (permissions, when to use, alternatives) even though annotations cover the safety profile. Adequate but with clear gaps for a 2-parameter nested-object tool.

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 100%, so the entity and company parameters are already documented in detail, including the NameOf/EmployeeRef/VendorRef requirement and PII exclusions. The description adds nothing beyond that schema baseline, so 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?

The description states a specific verb and resource ('Create a time activity in QuickBooks Online') and adds the return value. It is clearly distinct from create-invoice/create-bill siblings, but does not explicitly differentiate from create_task or update_time_activity.

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?

No guidance on when to use this versus update_time_activity or search_time_activities, and no prerequisites or exclusions. The context is only implied by the verb 'Create'.

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