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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds real value by enumerating the return payload (signing string, timestamp, chain, hosted fallback) and asserting no proof is created. It does not mention any auth/signing prerequisites, which is the remaining behavioral gap.

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 short sentences, front-loaded with the action and followed by the return shape and the explicit non-effect. Nothing redundant and no filler.

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?

With a full output schema and 100% parameter coverage, the description need not explain returns in depth and correctly doesn't. The only shortfall is the missing hand-off to the submit step, which an agent calling a two-phase sign flow would want spelled out.

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% and the nested options/meta and data fields are documented in detail in the schema itself, so the description adds no parameter-level meaning. Baseline 3 is appropriate when the schema carries the full burden.

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?

States a specific verb and resource ('Prepare a signature request for the selected Proofable checks') and immediately defines the boundary: it returns a signing string but 'does not submit the check or create a proof.' That negative scope cleanly separates it from proofable_verify / proofable_verify_submit without needing to name them.

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 'does not submit' clause implies this is a pre-step to a submit call, so usage is inferable. But it never says explicitly when to choose this over proofable_verify, proofable_verify_or_guide, or proofable_verify_submit, nor what the agent should do with the returned signing string next.

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