list_inbox_counts

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

No annotations are present, so the description must convey behavioral traits. It indicates the tool retrieves counts, implying a safe, read-only operation. However, it does not explicitly confirm idempotency, lack of side effects, or any authentication requirements beyond the optional API key parameter in the 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, well-structured sentence that conveys all necessary information without waste. Every word serves a purpose.

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 read tool with one optional parameter and no output schema, the description is largely complete. It defines the return scope (counts per category and label) and the intended use case (inbox sidebar). Minor gaps: it does not clarify what 'total' means or how labels are structured, but overall it is adequate.

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% (apiKey is documented). The description adds no additional meaning to the parameter beyond what the schema already provides. Baseline 3 is appropriate.

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 clearly states the tool retrieves unread and total counts per category and label for the inbox sidebar, listing specific categories (newsletter, transactional, etc.). This verb+resource combination distinguishes it from all sibling tools, which deal with different resources like contacts, campaigns, or automations.

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 implies the tool is for populating an inbox sidebar, but it does not explicitly state when to use it versus alternatives, nor does it mention any prerequisites or conditions. No exclusions or comparisons are provided.

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