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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true. The description adds genuinely new behavioral context beyond them: the caller must hold the signing key and the tool will not sign on their behalf, and sandbox mode carries no payment effect. It stops short of describing what the destructive effect actually is.

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 immediately by the authorization prerequisite. Nothing is padded or restated from the title.

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?

A destructive, non-read-only tool with a deeply nested required envelope, 0% parameter documentation and no output schema warrants substantially more explanation than is present. An agent learns the signing requirement but not the consequences of a successful or failed submission, nor how the result is returned.

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 two parameters, one of which is a nested object with eleven required subfields. The description explains none of them, contributing only the indirect signal that the envelope must already carry a signature and that mode=sandbox is non-monetary. For a payload this structured, the description should carry more of the 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?

The description states a specific verb and resource: "Submit an owner/agent-signed authority envelope." That is enough to separate it from read-oriented siblings such as xguard.authority.verify_receipt or xguard.authority.catalog, though the term "authority envelope" is only decoded by the schema, not the prose.

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?

It gives constraints ("Requires explicit key-holder authorization") and one disambiguation ("Sandbox is not a payment"), but offers no explicit when-to-use or when-to-prefer-another-tool guidance. An agent must infer from the sibling names when this submission path applies versus preflight or verify flows.

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