everything_count_stats

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds the useful behavioral context that no file list is returned and that breakdowns are high-level, but it does not disclose the top-200 sampling behavior for breakdowns, which is left to the parameter schema. No contradictions exist.

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?

Three short, purposeful sentences. The main purpose is front-loaded, the second sentence establishes when to use it, and the third maps to an optional parameter. There is no filler or redundant explanation.

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, combined with the rich parameter schema, safety annotations, and available output schema, gives an agent everything needed to select and invoke this tool correctly. No critical usage or behavioral information is missing.

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 visible nested schema actually provides strong descriptions for all three parameters: query syntax examples, the include_size boolean, and the breakdown_by_extension behavior. The description itself only echoes the extension-breakdown option and adds no extra meaning beyond the schema, so the baseline 3 applies.

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 opens with a concrete verb and resource: 'Get count and size statistics for files matching a query.' It also distinguishes itself from sibling search tools by explicitly saying it works 'without listing every file,' so an agent can tell it apart from everything_search and similar listing-oriented tools.

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 gives a clear decision context: use it as a 'fast way to understand the scope of a query without listing every file.' This implies the main alternative is a file-listing search, but it does not name sibling tools explicitly or state exclusions, so it stops short of a 5.

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