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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context by listing what the response includes: issuing authority, date checked, the authority's own wording, and a citation, which matters because there is no output schema.

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 description is a single front-loaded sentence with no filler. It moves from purpose to examples to return content efficiently.

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 single-parameter read tool with annotations covering safety and no output schema, the description is complete enough: it states the purpose, the scope, and the key return components. No critical calling information appears to be 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?

Schema description coverage is 100%, so the schema already documents the single 'volcano' parameter and its accepted spellings. The description's examples (Etna, Vesuvius, Kilauea, Reykjanes) add minor illustrative value but no syntax or format detail beyond the schema.

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 precise resource ('current official alert level') and scope ('of one volcano'), with examples that make the expected input concrete. This scope implicitly distinguishes it from list_alert_levels (multiple volcanoes) and alert_level_changes (historical changes).

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 implied by 'of one volcano' and 'current', but there is no explicit when-to-use guidance, no when-not-to-use guidance, and the sibling tools are not named as alternatives. An agent must infer that this is for a single volcano's current status rather than a list or change history.

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