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

Annotations already state readOnlyHint=false, destructiveHint=false, idempotentHint=false, so safety basics are covered. The description adds nothing beyond that: it does not say whether created schedules auto-generate/send invoices, how next_due/ends_on interact, or what retry behavior non-idempotency implies — all critical for a scheduling mutation.

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?

It is technically one short sentence, but this is under-specification rather than conciseness — there is no front-loaded actionable content and the sentence is grammatically broken.

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?

With 16 parameters at 0% schema coverage, no output schema, and only the safety annotations, the description would need to carry substantial weight to make this callable. It carries none, leaving the agent unable to determine required argument formats or scheduling semantics.

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 0% across 16 parameters, including non-obvious ones like items_json (a serialized string), day_of_week vs day_of_month, total_generated, and last_generated_at. The description provides zero compensating explanation, leaving required fields like items_json format entirely opaque.

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 restates the tool name ('Create a invoice_recurring') with no elaboration on what a recurring invoice is or what creating one produces. It never distinguishes this from siblings like invoice_create or expense_recurrence_create, and the grammar slip further reduces clarity.

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 indication of when to use this instead of invoice_create, invoice_recurring_update, or expense_recurrence_create. The only implicit signal is the verb 'Create', which the name already carries.

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