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

Annotations already state readOnlyHint=false, destructiveHint=false, openWorldHint=false, and idempotentHint=false, so the safety profile is covered. The description adds real context beyond them: the $0.01 cost, determinism, the three possible verdicts, an Ed25519-signed receipt, and four explicit boundaries of what the tool does not do.

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 tight sentences, front-loaded with the core action and cost, then the return values, then the boundary constraints. Dense and largely waste-free, with the negative constraints earning their place by preventing misuse.

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?

Return values are described well enough that a missing output schema is not fatal, but for a three-parameter tool with nested objects and 0% schema coverage, the description leaves the approval parameter and the expected shapes of authority/action undefined. Adequate but with clear gaps.

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 0% across three nested-object parameters, so the description carries the full burden. It loosely maps 'one proposed action' and 'one supplied authority envelope' to the action and authority params, but gives no shape/syntax detail and never mentions the approval parameter at all.

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 names a specific verb and resource: a deterministic comparison of one proposed action against one supplied authority envelope, with explicit output states. It clearly distinguishes itself from a generic approval/execution tool, though it does not name or route against its siblings scopeproof.preflight or scopeproof.verify_receipt.

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?

Usage is implied through four explicit non-capabilities (does not authenticate the issuer, grant permission, replace host approval, or execute/fetch the target), which draws useful boundaries. However, there is no positive 'use this when' guidance and no comparison to preflight or verify_receipt to select among the siblings.

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