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

Annotations already establish readOnlyHint and idempotentHint, so safety is covered. The description adds genuinely new behavioral context beyond that: the call is free (notable given paid siblings exist) and it exposes where schemas and signing keys live, which tells the agent this is a discovery/documentation endpoint.

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?

One sentence, front-loaded with the most decision-relevant token ('Free.') and then a tight list of covered topics. Every clause earns its place and there is no 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 parameterless informational tool with no output schema, the description adequately tells the agent what topics the response will address (product, flow, prices, schemas, keys). It could note the response format or whether the content is static documentation, but nothing essential to calling it correctly is missing.

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?

The tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. The baseline of 4 applies; no parameter semantics are needed or missing.

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 (KYA Brasil overview) and enumerates exactly what it covers: the product, credential flow, prices, and schema/key locations. That distinguishes it clearly from action-oriented siblings like kya_verify or kya_revoke, though it never uses an explicit verb such as 'returns' or 'explains'.

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 leading 'Free.' implies this is the no-cost orientation call to make before using paid siblings such as kya_verify_paid, which is useful routing context. However, it never explicitly says when to use this versus the other 14 tools, so the guidance remains inferred rather than stated.

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