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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only the vague 'market share' notion, without stating that it returns aggregated counts/shares rather than site records, nor mentioning pagination or run scoping behavior. Some value, but thin for a 22-parameter tool.

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 compact sentence with the operation front-loaded and no wasted words. It is efficient, though arguably under-specified for a tool with this many parameters rather than genuinely concise.

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?

An output schema exists and the input schema is fully documented, so return format and parameter meaning are covered. However, for a 22-parameter aggregation tool sitting next to a sibling search tool, the description omits the routing information an agent needs to pick this one correctly.

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?

Schema description coverage is 100%, so every parameter is already documented in the schema, including allowed facet values. The description adds no syntax, format, or interaction detail beyond what the schema provides. Baseline 3 applies when the schema does the heavy lifting.

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 specific operation ('facet aggregation') and resource (the website tech-stack dataset), with a parenthetical clarifying the aggregated outputs (technology / category market share). An agent can tell this is an aggregation tool, but the description makes no effort to distinguish it from the sibling datasets_techstack_search, which by naming convention shares the same filter surface.

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?

There is no guidance on when to use this tool versus datasets_techstack_search or datasets_techstack_item. The description never names an alternative or states a condition (e.g. 'use when you want counts by facet rather than matching site rows').

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