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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is fully covered. The description adds useful context about the data source (CBR daily ED807 directory) but does not describe rate limits, authentication needs, or what happens on failed lookups.

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?

A single sentence front-loads what the tool is (BIK directory) and then states its capabilities (search by BIK or name). Every element earns its place with zero redundancy or 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?

For a simple two-parameter lookup tool with no required arguments, full annotation coverage, and no output schema, the description adequately conveys the source and search options. It could mention what fields are returned, but an agent can reasonably infer bank details and the omission is minor for this complexity level.

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%: both bik and name have clear descriptions that state format and matching behavior. The tool description only restates that search can be by BIK or name, adding no new meaning beyond what the schema already provides, so the baseline of 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?

The description names a specific resource (BIK directory of Russian banks) and a specific action (search by BIK or bank name), clearly distinguishing it from sibling tools that check sanctions, disqualified persons, etc. An agent can immediately tell what this tool does without opening the schema.

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?

The description implies usage by stating the two search criteria (BIK or bank name), but it does not explicitly say when to use this tool versus alternatives such as org_lookup or get_reference. No when-not conditions or prerequisites are given, leaving the agent to infer context.

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