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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds a bit of context about coverage and freshness but does not disclose response shape, caching, or any operational behavior beyond the trigger. That modest additional value justifies a 3.

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 sentence with no wasted words and places the usage trigger upfront. It is as concise as possible while still conveying when to use the 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?

For a parameterless, read-only list tool with strong annotations, the description provides enough contextual signal about city coverage and freshness. The main gap is that it does not explicitly state the return value (e.g., a list of covered cities with freshness indicators), relying on the title for that meaning.

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?

There are no parameters and schema description coverage is 100%, so there is no parameter burden for the description to carry. The baseline for zero-parameter tools is 4, and the description appropriately needs no param-specific detail.

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 title 'List Covered Cities' supplies the action and resource, and the description clarifies that Dizko city coverage or freshness is the subject. It is clear enough for an agent, though the description itself leans on a usage trigger rather than an explicit verb and resource statement. It does not strongly differentiate from get_city_pulse, but they are clearly different in scope.

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 explicitly states when to use the tool: 'when a user asks about Dizko city coverage or freshness.' This gives a clear context match, but it does not list exclusions or name alternative tools, so it falls just short of full guidance.

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