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

With no annotations, the description carries the full burden and does disclose meaningful side effects: a reminder email goes to the customer when the shop has service due emails enabled, and repeat_months causes a follow-on due record when this one is marked done. It omits permission/auth requirements and idempotency behavior, so it stops short of a 5.

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?

Three short sentences, front-loaded with the core action and example, then the required inputs, then the recurring/email behavior. Every sentence contributes; the example adds clarity rather than padding.

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?

There is no output schema, but return values are not explained either, and job_id plus permission/visibility constraints around the reminder email are unaddressed. For a six-parameter tool with zero schema description coverage, the description is helpful but not fully 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 coverage is 0%, so the description must compensate. It explains title, due_on and the semantics of repeat_months beyond the schema's bare min/max ('marking it done sets the next one'), and shop/customer are implied by 'customer's next service' and 'the shop'. The job_id parameter is never mentioned, leaving a real gap at low coverage.

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: 'Record when a customer's next service is due', with a concrete example (yearly furnace tune-up) and the owner/office framing. It is clearly a creation tool and thereby separable from siblings such as services_updateDue, services_completeDue and services_listDue, though it never names them explicitly.

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 ('Give a title, the due date and optionally repeat_months...') but gives no explicit when-to-use versus when-to-use-an-alternative guidance. An agent must infer on its own that this is the create path and that services_updateDue handles edits.

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