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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds nothing beyond that: no note on what gets created, whether duplicates are possible (non-idempotent), or whether active/next_due defaults are applied.

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 one short sentence, but the brevity is under-specification, not efficiency. There is no front-loaded content to speak of since the sentence contains no information beyond the tool name.

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?

A 12-parameter mutation tool with no output schema and no annotation-level description supplementation. The description leaves the agent without guidance on required field meanings, scheduling semantics (day_of_week/day_of_month vs frequency), or lifecycle fields, which is far from complete.

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 12 parameters, including four required ones, and the description supplies zero meaning for any of them. Fields like next_due (integer, presumably epoch), is_active (integer rather than boolean), total_generated, and last_generated_at are ambiguous and would benefit greatly from narrative clarification.

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 expense_recurrence'), adding only the verb that is already implied by the '_create' suffix. It gives no indication of what a recurrence represents, what it schedules, or what distinguishes it from expense_create or invoice_recurring_create among the many siblings.

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 when-to-use, when-not-to-use, or alternative is named. With siblings like expense_create, expense_recurrence_update, and invoice_recurring_create in the same listing, the agent gets no routing help at all.

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