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

With no annotations provided, the description carries the full burden. It discloses that the tool does not sign on behalf of the user ('sign with YOUR key on YOUR machine'), explains ring gating behavior, and notes that the gate applies to amplification rather than content. This is substantial transparency, though it could mention non-mutation explicitly.

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 moderately concise, leading with the core purpose and return shape, then expanding on rings and gating. Each sentence adds meaningful context, though the tone is slightly ornate ('THE COMMONS', 'the gate is on what the library AMPLIFIES'), which prevents a perfect score.

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 an 8-parameter tool with no output schema, the description provides a solid high-level understanding: what the tool returns, the signing workflow, and ring semantics. It does not detail the 'fields' part of the return or next steps after signing, but it gives sufficient context for an agent to select and invoke the tool correctly.

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 75%, so the baseline is 3. The description adds conceptual clarity for the 'ring' parameter (explaining each ring's behavior) and reinforces the 'member' parameter as 'your public key', but it does not add details for body or subject, which lack schema descriptions. Overall, the description complements but does not significantly augment 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 clearly states the tool's function: it returns the canonical bytes to sign for creating a shelf, specifying the exact return shape ({fields, signable}) and the resource (shelf). It distinguishes from sibling signable tools by emphasizing that a shelf is a covenant key with cards, not an account, and by describing ring options.

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 strong usage context by positioning this as 'step 1 of stocking your own shelf' and explaining ring semantics (private, shelf, commons). It does not explicitly exclude alternatives or name sibling tools, but the context makes it clear when this tool is appropriate.

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