sign_action

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

With no annotations, the description carries full burden. It discloses side effects (writes save_path when set), return format (tuple with signature block), and constraints (canonicalization, no top-level signature block). It does not discuss authentication or error handling, but the level of detail is good.

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: first states core purpose, second lists use cases, third covers side effects and return format. No wasted words, front-loaded with key information.

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 4 parameters (2 required), nested payload object, and output schema exists, the description adequately explains the signing process, validation for typed actions, side effect, and return. It lacks error scenarios and auth details, but the presence of output schema reduces the need to describe return structure.

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 baseline is 3. The description adds extra meaning: canonicalization per SPEC.md §4, caution against including signature block, and context for action_type (e.g., 'Typed actions validate required payload fields'). This elevates it above 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 clearly states the tool signs a universal provenance action envelope with the active Ed25519 identity. It lists specific use cases (CI steps, IaC changes, etc.) and distinguishes typed actions that validate payload fields. This purpose is unique among siblings like verify_envelope or create_envelope.

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?

Explicit use cases are provided (CI steps, DB migrations, etc.), and it mentions that typed actions validate payload fields before signing. However, it does not explicitly state when not to use this tool or mention alternatives, though the context is clear enough for an AI agent.

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