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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful context beyond them: the window is capped by the API key's plan tier (Free 7, Pro 30, Intelligence 90), which an agent needs to know before requesting large day ranges.

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?

Two sentences, front-loaded with the metric definition and followed by the operational cap. Dense but no filler; every clause carries meaning.

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?

There is no output schema, so the description should carry return-value context, and it only gestures at it ('with its domains and last seven days'). For a 4-parameter, 0-required aggregation tool the plan-tier note is helpful, but the locale parameter and result shape remain unexplained.

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 50%, so the description must compensate, and it partially does: 'domains' maps to the domain enum, 'last seven days' maps to the days parameter and its default, and 'per country' maps to country. The locale parameter is never mentioned and no format/syntax details are added 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 names a specific resource (SeekMap's Change Heat per country) and states what it measures: verified change against the prior day, broken out by domain over the last seven days. It is distinguishable from siblings like get_change or latest_changes by its per-country aggregation, though it never explicitly contrasts itself with them.

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?

No when-to-use guidance is given and no sibling is named as an alternative. The plan-cap sentence describes a constraint on the window, not a condition for selecting this tool over another.

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