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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: the join semantics across entities and the crucial null interpretation — 'treat null as not yet joined, never as no link.' This is not merely restating annotations and materially improves correct usage.

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, purposeful sentences. The first sentence states the core purpose and scope; the second delivers high-value usage patterns and the critical null-semantics warning. No filler or repetition of annotation or schema content.

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 12-parameter tool with 100% schema coverage, an output schema, and safety annotations, the description is largely sufficient. It supplies the essential domain-level context: what the capability spine is, how it joins entities, and how to interpret unresolved links. A small gap is that it does not guide an agent on combining filters or when to use sibling tools, but the schema fills most remaining needs.

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 description's mentions of min_guides, role, and capability_detail largely restate what the schema already documents; the novel null-semantics guidance concerns output fields rather than parameter meaning. It adds no significant parameter-level information beyond 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 uses a specific verb and resource: 'Traverse the capability spine joining books, guides, KSAO-grade elements and jobs.' This clearly distinguishes it from sibling tools like get_guide and list_guides, which operate on individual guides or guide lists rather than the cross-entity capability graph.

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: min_guides=2 for cross-cutting capabilities, role=<role> for job requirements, and capability_detail=<slug> for hydrated package details. It does not, however, state when to prefer a sibling tool or explicitly say when not to use this tool, so it falls just short of a 5.

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