clients_anaf_lookup

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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so safety is covered. The description adds genuine context beyond them: the data comes from an external public registry and no client record is persisted, plus it enumerates the returned field categories.

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?

Two sentences, zero waste — the action and the non-persistence constraint come first, followed by the return payload and intended follow-up. Nothing redundant.

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?

For a two-param read-only lookup, the description covers purpose, the external source, and the return shape in lieu of an output schema. It omits the companyId override and any caveats about external-registry failures or rate limits, which would round it out.

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%, so both parameters are already documented by the schema. The description reinforces that CUI is the lookup key but says nothing about the companyId override, so it adds no meaning beyond the schema. Baseline 3 applies.

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 — look up company details by CUI in the ANAF public registry — and explicitly contrasts with client creation. It does not name the nearest sibling lookups (clients_from_registry, clients_vies_lookup), so an agent must still infer which lookup source fits.

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?

"Without creating a client" plus "can be used to populate a clients_create call" gives clear context for when this tool is the right choice and what to do next. There is no explicit when-not guidance or routing to the VIES/registry alternatives.

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