dataset_class_stats

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

Annotations only declare readOnlyHint/destructiveHint safety, so the description adds real value by disclosing the default shape of the response (histogram/heatmap groups stripped, omitted groups named in the summary) and the exact opt-in that restores them. It stops short of describing structure of the per-class counts themselves, and much of the payload-shaping detail also appears in the include_histograms schema description.

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?

Two dense sentences, with the core purpose and accepted reference forms front-loaded and the default/opt-in behavior following. The parenthetical enumeration of histogram and heatmap groups duplicates the schema description of include_histograms, which is minor waste.

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 explaining the return content, and it does so reasonably: it states the tool returns per-class annotation counts and describes the default trimming and the summary note about omitted groups. It does not describe the shape of the per-class count entries themselves, which leaves a small gap.

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 both parameters are already documented, including the accepted ref formats and the histogram enumeration. The description restates the same accepted reference forms and the same omitted-group list, adding little semantic value beyond the schema; 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?

States a specific verb+resource ('per-class annotation counts for a dataset') and names all three accepted reference forms (slug, owner/slug, ul:// URI). This is clearly distinguishable from nearby siblings like datasets_get or explore_datasets, which do not return per-class statistics.

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?

Gives clear context for the one meaningful choice: by default the bulky groups are omitted, and 'pass include_histograms: true to get the full payload unmodified.' That tells the agent when to use the non-default path, but names no alternative sibling tool and gives no explicit when-not-to-use guidance.

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