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

Annotations already declare read-only, closed-world, idempotent, and non-destructive behavior; the description reinforces this and adds non-obvious behavioral facts: depth is hard-capped at 4 hops, profile independently sets the exploration budget with deep consuming 5x quota, profile overrides depth when both are given, and relevance=low/no_path_reason means the path is absent and must not be cited as evidence.

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 front-loaded with the core purpose, then follows a logical structure: examples, alternative tools, parameter semantics, and a usage caveat. Every sentence carries actionable information without filler, and the use of bullets and bold makes it scannable.

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 five parameters, an output schema, and rich annotations, the description covers purpose, routing boundaries, parameter behaviors, edge cases, and operational constraints. An agent has everything needed to decide whether to call this tool, how to configure depth/profile, and how to interpret success and failure signals.

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, but the description adds substantial meaning beyond the schema: it defines depth ordering (L1<L2<L3), explains that profile is independent of depth, states that profile determines the actual budget when both are provided, and details the budget implications of each profile. It also clarifies as_of's format and the interpretation of result caveats.

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 verb and resource: it explains the 'why, principles, and pros/cons' of architecture/space via causal paths, and grounds this with concrete example questions. It also explicitly distinguishes itself from four sibling tools, so an agent can tell them apart without inspecting schemas.

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?

It clearly states when to use the tool ('when asking why questions') and routes to named alternatives with specific conditions: evidence_for for a single known causal line, path_between for mere connectivity, k_snippets for numbers/provisions, and define for term meanings. This is explicit when-to-use and when-to-use-other guidance.

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