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

Annotations already declare readOnly/idempotent/non-destructive, so the description focuses on domain behavior instead: the exact returned fields, the de minimis ok/warning/breach states, per-zone smart hints, and the non-applicability guard for UK/mainland entities. That is useful context beyond the annotations, though nothing is said about what happens when the company argument is ambiguous or stale data.

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?

Front-loaded with purpose, then return contents, then the applicability caveat, then trigger conditions — a sensible ordering. The enumeration of returned fields is dense but each item is decision-relevant; only the parenthetical smart-hint examples are borderline 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, so the description carries the burden of describing return values, and it does so concretely (qualifying/non-qualifying split, de minimis status, zone name, substance declaration, hints). Combined with the applicability condition, an agent has everything needed to call and interpret this 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 100% and the single optional `company` parameter is fully documented in the schema, so the baseline of 3 applies. The description only adds the scoping notion of 'the active company's', without new syntax or selection rules beyond what the schema states.

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 ('Get the active company's QFZP status for UAE Corporate Tax') and immediately enumerates what the status comprises: income split, de minimis state, zone name, substance declaration. This is clearly distinguishable from sibling status tools such as get_gifi_status or get_vat_summary.

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?

Explicit triggering conditions are given ('Use when the user asks about QFZP status, whether they still qualify, their de minimis headroom, or whether they'll owe 9% CT'), plus an exclusion: returns applicable=false for UK or UAE mainland companies. It does not name a sibling as the alternative for those cases, which keeps it short of a 5.

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