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

The description discloses a non-obvious behavioral trait: ksao_type/canon_component_id are null by design, and null must be interpreted as 'not yet joined' rather than 'no link.' This is exactly the kind of semantic trap an agent would otherwise misread. It also frames the tool as a read/traverse operation consistent with the readOnlyHint annotation, and no contradiction exists.

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?

Three sentences, front-loaded with the core purpose, followed by the most important usage patterns and a critical null-semantics warning. There is no filler, repetition, or unnecessary abstraction. Every sentence earns its place.

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?

Given the tool's complexity — 12 optional parameters, four joined entity types, and an output schema — the description covers the essential conceptual model, the key parameter routes, and the critical interpretative rule about nulls. The detailed per-parameter schema handles the remaining specifics, so nothing an agent needs to invoke this correctly is missing.

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 the baseline is 3; the schema already documents every parameter. The main description largely restates the schema's guidance for min_guides, role, and capability_detail rather than adding genuinely new parameter semantics. It adds mild framing value, but not enough to push above the baseline.

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 uses a specific resource ('the capability spine') and a deliberate verb ('traverse') while naming the entities being joined: books, guides, KSAO-grade elements, and jobs. This clearly differentiates it from guide-focused siblings like list_guides and get_guide, even without naming them. The scope is unambiguous.

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 provides concrete conditional usage: min_guides=2 for cross-cutting capabilities, role=<role> for job requirements, and capability_detail=<slug> for a hydrated package. It does not explicitly state when to prefer list_guides or get_guide instead, so it falls short of explicit alternative routing, but the usage context is otherwise clear.

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