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

Annotations declare write, open-world, non-destructive, but the description adds real behavioral context beyond them: daily cadence, the exact trigger events, alert delivery channels, and that re-adding updates rather than duplicating the watch. It stops short of disclosing auth/permission requirements, failure behavior, or whether alerts are deduplicated, which keeps it from 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 tight sentences, front-loaded with the action and scope, then alert delivery, then the update-on-re-add caveat. No filler and no restatement of 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?

With no output schema and only partial annotation coverage, the description supplies the essential behavioral picture: cadence, monitored event classes, and delivery channels. Missing pieces such as NIP validation expectations, permission requirements, and what a successful add returns are minor but real gaps for a write 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 coverage is only 20% (just the accounts array), so the description must carry weight and it partially does: it clarifies the purpose of accounts ("the specific accounts you pay to") and ties webhook_url/e-mail to the alert mechanism. It says nothing about nip (the required field and its expected Polish NIP format), label, or the constraints on the account list, leaving meaningful gaps.

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 concrete verb and resource ("Start daily monitoring of a Polish contractor") and enumerates exactly what is monitored: VAT status, whitelisted bank accounts, and KRS liquidation/bankruptcy/restructuring. That specificity clearly separates it from point-in-time siblings like check_vat_whitelist and vies_check, but no sibling is named, so the differentiation is inferential rather than explicit.

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?

Usage is implied rather than stated: continuous monitoring for a contractor you transact with, with alerts by webhook and/or e-mail. The note that "Re-adding updates the watch" is genuinely useful operational guidance (idempotent re-subscription), but there is no explicit when-to-use versus check_vat_whitelist/contractor_due_diligence, and no stated prerequisites (e.g. valid NIP, account verification).

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