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 safety is covered. The description still adds real context beyond them: the values reported are remaining capacity 'in this period', and the tool doubles as a diagnostic step after a refusal. It does not mention auth requirements or what happens if the plan is exhausted.

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 with no filler: the first states what is returned, the second when to call it. The most decision-relevant information (the quota fields) is front-loaded.

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 zero-parameter, read-only, closed-world tool with an output schema that documents the return shape, this covers everything an agent needs: what it shows, when to reach for it, and that it is a safe diagnostic call. Nothing material is 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?

There are zero parameters, so there is no parameter meaning to explain and the baseline of 4 applies. The description correctly adds nothing spurious about inputs.

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 the exact resource and scope: remaining searches, campaigns, reply drafts and stored leads for the signed-in account in the current period. That is specific enough to separate it from data-listing siblings such as get_my_leads or list_my_campaigns, though it never names those alternatives or states a verb for the operation itself.

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?

It gives two concrete triggers: when the user asks about their plan or limits, and as a follow-up after another tool reports something is not included. That is a clear usage context, but there is no explicit when-not guidance or named alternative tool for the same need.

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