key.evolve

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

Discloses key behavioral traits: pure and deterministic, UNSIGNED requiring a Swordsman at Rung 1, and the resulting key structure with walks[], prior, and fresh κ. No annotations are present, but the description covers the important behavioral constraints.

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 compact, front-loaded with the action, and every sentence adds relevant information; no filler or redundant restatement.

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?

Covers input forms, the default-key path, output key evolution, and signing context. It omits details such as error handling and explanation of bake/κ, but is reasonably complete for a domain-specific tool.

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?

All three parameters have meaningful descriptions that extend the loose anyOf schemas, especially key (JSON/sigil/path) and walk (step forms). The semantics are enriched beyond the schema even if some domain terms remain terse.

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?

Clearly states the operation: append a walk to a City Key, with a deterministic, pure outcome. It distinguishes itself by emphasizing UNSIGNED and default-key behavior, though it does not explicitly contrast sibling tools like key_derive.

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?

Provides operational details (walk forms, default key, unsigned status) but no explicit guidance on when to choose this over sibling tools such as key_derive, guide_search, or lattice_move.

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