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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context beyond the annotations: the meaning of limit -1, the fact that adding/disabling are unlimited, and that only edits consume allowance. This is useful domain behavior not derivable from the schema or annotations.

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 sentences with no filler. The primary action and resource appear first, and the clarifying detail about limit -1 and unlimited operations is placed immediately after, making it easy for an agent to parse quickly.

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?

The description is fully adequate for a zero-parameter read-only tool. It explains the key business rule (only edits count), the meaning of the unlimited sentinel, and the distinction from related keyword mutation tools. The presence of an output schema covers return value details, so no additional information is needed.

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 and the schema covers 100% of the surface, so there is nothing for the description to add about parameter meaning. With no parameters, the baseline is 4, and the description appropriately focuses on the return semantics 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 uses a specific verb and resource: 'Get the current monthly keyword-EDIT allowance and how much is used.' It also clarifies the semantics of limit -1 and explicitly distinguishes editing from adding/disabling keywords, which helps differentiate it from sibling tools like edit_keyword, add_keywords, and disable_keyword.

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 clearly implies when to use this tool: when needing to check the keyword-edit allowance before performing edits. It states that adding and disabling keywords are unlimited, so the tool is only relevant for edit operations. However, it does not explicitly name an alternative tool or spell out 'use this instead when...' so it stops short of a full when/when-not guide.

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