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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly indicates a read-only operation ('remaining free lookups') with no side effects, which is transparent enough. It also clarifies the client scope (IP or signed-in account), which is useful context. It could be slightly more explicit about being non-destructive, but the phrasing strongly implies it.

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 two short sentences with zero filler. The core purpose is front-loaded, and the second sentence adds essential context about the shared pool. Every word earns its place.

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 tool with no parameters and no output schema, the description fully explains what the tool does (returns remaining free lookups), who it applies to (the client), and how the quota is shared across lookup types. An agent has all the information needed to call it correctly and interpret the result (a number).

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?

The tool has zero parameters, so the schema coverage is effectively 100%. Baseline for no-parameter tools is 4. The description adds no parameter-specific details because there are none to describe. It correctly focuses on the output and scope instead.

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's purpose: returning the remaining free MCP lookups for the client. It names the specific resource (free lookups) and scope (per IP or signed-in account), and it implicitly distinguishes itself from the sibling lookup tools (which perform lookups, not quota checks). No ambiguity.

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 explains that the quota is a shared pool for USDOT, MC/MX/FF, and name search, which hints that it applies to all sibling lookups. However, it does not explicitly state when to use this tool (e.g., before performing lookups) or when not to use it. The guidance is implied rather than explicit.

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