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

Annotations already establish readOnlyHint=true, destructiveHint=false, openWorldHint=false. The description adds real behavioral context beyond them: the call is free, is not counted against the allowance, and its output varies by whether an API key is present. It stops short of describing response shape or failure modes, which keeps it out of the top band.

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?

A single sentence that front-loads the usage trigger and then lists the returned metrics in a compact clause. No filler, no repetition of the title or annotations.

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 no output schema, the description carries the burden of telling the agent what comes back, and it does so by enumerating the three counters. Combined with the free/not-counted note and the auth-conditional behavior, an agent has everything needed to call this correctly before a large task.

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 takes zero parameters, so the schema has nothing to document and the baseline is 4. The description correctly implies a parameterless call with its conditional 'with an API key' phrasing, adding the only parameter-adjacent nuance that exists.

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 concrete resource (today's allowance) and enumerates exactly what is reported: requests in the current 5-hour window, distinct companies today, and contact reveals with an API key. This is clearly distinguishable from the sibling lookup/search tools, which all retrieve entity data rather than account consumption.

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 an explicit usage trigger: 'Use this before a large task,' which tells the agent when to call it. It does not name alternatives or exclusions, but the sibling tools (find_people, lookup_company, search_companies) serve wholly different purposes, so no routing ambiguity exists.

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