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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered upstream. The description adds that plan and page-view-limit state are surfaced, but that is largely return-content information already carried by the output schema. No auth/permission requirements or failure behavior (e.g., unconnected client) are described, so added behavioral value is modest.

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 core purpose followed by usage triggers. The enumeration of reported fields is dense but every item earns its place by telling the agent what context it gains from calling.

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?

With an output schema present, return-value explanation is not required, and annotations cover the safety profile; the description supplies purpose and usage triggers for a one-parameter tool. It is nearly complete, though a note on the unconnected/no-domain case would close the last gap.

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%; the single optional `domain` parameter is fully documented in the schema, including its default. The description's mention of "which domain other tools will use when none is given" reinforces the defaulting behavior but adds no syntax or constraint detail beyond the schema. Baseline 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?

Uses a specific verb ("Reports") plus a concrete resource (the signed-in CookiePal account) and enumerates what that includes: user, organisation, default domain, and each domain's plan and page-view limit status. An agent can distinguish this from siblings like list_domains or plan_check because it describes reporting the identity/default context rather than enumerating or checking a specific plan.

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?

Gives two explicit triggers: "Use it to confirm a connection, or to find out which domain other tools will use when none is given." That covers the main when-to-use cases well. It doesn't name alternatives (e.g., list_domains for full domain enumeration) or state when not to use it, so it stops short of a 5.

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