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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context: it works offline from a curated knowledge base, returns likely causes and fixes, and links to Korean step-by-step guides. This goes beyond the annotations without contradicting them.

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 dense sentence front-loads the action and then efficiently specifies supported sources, output contents, language, and offline behavior. Every part 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 single-parameter read-only lookup tool, the description fully covers the input format, output contents, language, and operational constraint. The sibling tools are all checkers, so no additional routing guidance is needed.

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% and the schema already describes the single 'error' parameter with examples. The description adds context about supported error sources but no additional parameter-level constraints or format details, 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 states a specific verb ('Explain') and a clear resource ('TLS/SSL certificate error message'), and enumerates the supported source ecosystems. This distinguishes it from sibling tools that check certificates, DNS, or expiry rather than explaining an existing error.

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 clearly implies the trigger: when an agent has a TLS/SSL error string, this tool returns causes, fixes, and guides. It does not explicitly name alternatives or state when not to use it, so it lacks explicit exclusions, but the input type and offline knowledge-base behavior provide strong contextual guidance.

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