Draw a business capability map

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

With no annotations, the description carries the full burden and discloses more than the bare operation: it returns a Mermaid diagram (not an image), uses three distinct encoding dimensions, and explains that fill and outline are independent axes so provenance of the heat judgment survives in the output. It stops short of covering edge behavior (orphan nodes, missing parents, defaults for omitted heat/confidence) but is strong for a rendering 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?

Two dense sentences, front-loaded with the core function and encoding, then a short rationale for the two-axis design. The bilingual duplication (Japanese and English) roughly doubles the length, but this mirrors the tool's ja/en/both language support and every sentence carries substantive information about behavior.

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 well covered: all 3 parameters and all 6 nested fields are documented in the schema, and the description explains how inputs map to visual output. The main gap is the return value: the description says 'returns as a Mermaid diagram' but never states whether the agent receives Mermaid source text, which is the likely intended meaning, and there is no output schema to resolve the ambiguity. Edge-case behavior for inconsistent hierarchy data is also unaddressed.

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 coverage is 100%, so the baseline is 3 and the schema already explains each parameter, including confidence's role as an outline style on an axis independent of the fill. The description adds some value beyond the schema by specifying the concrete encodings (solid/dashed/dotted lines, ● △ × marks) and the low/medium/high fill mapping, but the marginal gain over the schema is modest.

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?

Uses a specific verb-resource pair ('Draw a business capability map as a nested Mermaid diagram') and specifies the exact visual encoding: subgraphs for hierarchy, fill for heat, outline style plus marks for confidence. The output format and encoding scheme make it immediately distinguishable from sibling diagram tools (diagram_value_stream, diagram_adm_cycle) and from content tools like draft_capability_map.

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 makes the usage context inferable: when a capability map is needed as a visual Mermaid diagram with heat and confidence axes, this is the tool. However, it never explicitly names alternatives such as draft_capability_map or check_capability_map, nor states when NOT to use it, so routing must be inferred from the diagram_* sibling names rather than from the description.

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