elba_lookup_inn

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 useful traits: the upstream source (egrul.nalog.ru), that no key is required, and a real data limitation (addresses are not returned by the FNS search). It also flags the 'terminated' field as a blocker for billing. Missing are error behavior for an unknown/invalid INN and any throttling or freshness notes, which keeps it below 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?

The purpose, output field list and data source are front-loaded in the first sentence, and the later sentences each add distinct value (address limitation, mapping to elba_create_contractor, terminated warning). It is dense — four clauses separated by semicolons — but nothing is filler.

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?

An output schema exists, yet the description still summarizes the key returned fields and their business meaning (terminated blocks invoicing), which helps the agent decide next steps. Combined with the source disclosure and the create_contractor mapping, an agent has enough to call it correctly; only invalid-INN handling is left unaddressed.

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% and the single 'inn' property has no description, only a title. The description establishes that INN is the lookup key against the FNS registry, which is meaningful, but it never gives the expected format (10 digits for organizations, 12 for ИП), leaving the only parameter underspecified.

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 specific verb-and-resource pair: fetch organization/ИП requisites by INN from the FNS EGRUL/EGRIP registry, and enumerates the returned fields (full/short name, KPP, OGRN, head, registration and termination dates). It never contrasts with the confusable siblings elba_find_contractor / elba_get_contractor / elba_organizations, so an agent still has to infer which lookup to prefer.

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?

It gives concrete operating guidance: works without an API key, does not return addresses, results should be cross-checked against the client's own data, and a 'terminated' result means no invoice may be issued. It also tells the agent how to feed the result into elba_create_contractor (name vs short_name), which is real routing value. It stops short of stating when to use elba_find_contractor instead.

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