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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), so the bar is lower, yet the description still adds real behavioral value: rights are 'AS DECLARED in config — not asserted by this tool,' and 'Technical availability is NOT a legal right to use or redistribute the data.' That tells the agent how to interpret the output's epistemic status, which annotations cannot convey. It does not describe pagination or output format limits, so 4 rather than 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 core claim is front-loaded, but the body is a dense run-on that stacks parenthetical qualifiers, and the trailing Russian sentence duplicates the English content verbatim rather than adding information. Every sentence does address the tool's content, yet the structure is heavier than it needs to be for a one-parameter read tool.

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, so return values need not be explained, and annotations cover safety; the description still usefully frames what the card contains and warns against misreading declared rights as granted rights. The notable gap is the absence of any when-to-use guidance relative to the sibling tools, which keeps it from a 5.

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 description coverage is 100% and the sole optional parameter source_id is already documented in the schema (return one source's card by ID, empty = all sources). The description does not restate or extend that parameter's semantics, so the baseline of 3 for fully covered schemas 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?

The description states a specific resource — a machine-readable trust card of the registry itself — and enumerates the content categories it returns (sources with provenance, declared rights, coverage, grounding invariants). That is far more specific than a name restatement and is clearly a different domain from the sibling tools (check_counterparty, lookup_company, search_companies). It stops short of an explicit comparison to those siblings, so it lands at 4 rather than 5.

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 only implied: an agent can infer it should call this to inspect provenance, declared rights, and coverage before trusting or redistributing registry data. There is no explicit statement of when to call this versus the sibling lookup tools, and no prerequisites or exclusions are given. The caveat about legal vs technical availability is a limitation disclosure, not usage routing.

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