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

It discloses non-obvious behavior around unresolved joins: 'ksao_type/canon_component_id are null by design where unresolved—treat null as not yet joined, never as no link', which prevents misinterpretation. It also explains that capability_detail hydrates elements and books for one package. These go beyond the readOnlyHint/destructiveHint annotations and add genuine behavioral context.

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 description is three sentences with no filler: core mechanism, targeted parameter recipes, and the critical null caveat. It is front-loaded with the primary action and each sentence serves a distinct purpose.

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?

An output schema exists, so return-value details are unnecessary. The description covers the main traversal modes, the most valuable filters, and the important null semantics. With all 12 optional parameters documented in the schema, nothing essential for invoking the tool 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?

The input schema already documents all 12 parameters (100% coverage), so the baseline is 3. The description adds extra meaning by explaining that min_guides=2 yields the cross-cutting spine, role filters by job requirement, and capability_detail returns a hydrated package, plus the null semantics for ksao_type/canon_component_id. This is useful enrichment over the schema.

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 states a specific action—'Traverse the capability spine'—and names the resources involved (books, guides, KSAO-grade elements, jobs), making the tool's purpose concrete. It is clearly distinct from siblings like list_guides or get_guide, which focus on single entities rather than cross-entity traversal and filtering.

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 gives explicit usage recipes: 'Use min_guides=2 for the cross-cutting capabilities', 'role=<role> for what a job requires', and 'capability_detail=<slug> for one package with its elements and books hydrated'. It also clarifies null semantics. However, it does not explicitly contrast with sibling tools or state when not to use this tool, so it falls short of full exclusion guidance.

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