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

Annotations already declare readOnlyHint, destructiveHint false, and openWorldHint false, so the safety profile is settled. The description adds that results come from a real algorithm engine rather than LLM generation (a useful determinism/trust signal) but omits the multiple-comparison adjustment behavior and assumptions (normality, variance) that matter for interpreting a Tukey HSD result.

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?

It is short and front-loaded with the method name, then the usage trigger, then the return value. The bracketed title partially duplicates the tool title in annotations, which is minor waste but not harmful.

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 one-parameter, read-only statistical tool with full schema coverage, the description supplies the essential picture: input grouping, when to call, and what comes back. The lack of an output schema makes the terse return note slightly thin (no mention of adjusted P vs. raw P or per-pair ordering), but overall it is sufficient to invoke 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% for the single required parameter, including the {group name: [values...]} shape. The description adds no further meaning about the parameter (e.g. minimum group count, handling of missing values), so the baseline of 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 names a specific statistical procedure — Tukey HSD pairwise comparison across multiple groups — and states the return value is pairwise P values. It does not explicitly contrast itself with statistically adjacent siblings such as act_dunn or act_two_way_anova, so it falls short of full sibling differentiation.

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?

It gives a clear trigger condition: use after an ANOVA has been run and the user wants pairwise comparisons among groups. It does not state when NOT to use it, e.g. nonparametric data should route to act_dunn, which is a real gap given that sibling exists.

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