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

The annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds genuine context beyond this: the operation is run by a real algorithm engine rather than generated by an LLM, which tells the agent the output is deterministic. It says nothing about performance, size limits, or failure modes beyond the schema.

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 definition is two short clauses with the intent front-loaded and the return value stated second. The bracketed title tag repeats the tool name and title, so it is slightly redundant, but nothing else is wasted.

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 input side is fully covered by the schema and the description hints at the return type ('returns: clustering heatmap'). However, no output schema exists, and the description does not say whether the result is an image, a file path, or a data structure, which is a meaningful gap for a plotting tool.

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?

Only one parameter is accepted, and the schema documents it exhaustively: matrix shape, rows/cols, optional groups, p_values, log2fc, and the exact rejection message when it is missing. The description adds no parameter detail of its own, but because schema coverage is 100%, the baseline of 3 is appropriate.

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 verb-and-resource pair ('draw metabolite clustering heatmap'), which is clearly distinct from the nearby metabolomics siblings such as act_metabo_pca, act_metabo_volcano, and act_metabo_plsda. It does not explicitly say which sibling to use instead, so it falls short of a 5.

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 phrase 'user wants to draw a metabolite clustering heatmap' implies the trigger condition, so an agent can infer when to call it. However, the description gives no exclusions, prerequisites, or pointers to alternative tools when a heatmap is not what the user wants.

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