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

With no annotations, the description carries the behavioral disclosure burden. It mentions that the tool is 'Free' and lists the data points it exposes, which strongly implies a read-only informational operation. However, it does not explicitly state absence of side effects, data freshness semantics, or any access requirements.

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 no filler. The 'Free' qualifier is front-loaded, and the remainder is a compact list of concrete metrics, making it easy to scan.

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 informational tool with no output schema, the description is sufficient: it states cost, enumerates the reported metrics, and gives the temporal detail about the last survey. An agent can confidently invoke this tool without further context.

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 baseline is 4. The description adds meaningful context about what the parameterless call returns, which fully removes invocation ambiguity.

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 identifies what the tool reports: counts of endpoints on file, bought endpoints, charge-without-delivery behavior, and last survey date. It lacks an explicit verb like 'get' or 'list,' but the resource and output metrics are specific enough. It does not explicitly differentiate itself from sibling tools, though the 'coverage' name and title help.

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?

No guidance is given about when to use this tool versus mizan_check or mizan_report. The description implies it is a summary/coverage status tool, but there are no stated conditions, exclusions, or references to alternatives.

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