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

With no annotations, the description carries the full burden and does add one valuable fact: an operator Bearer token must be supplied in arguments.token. It does not say whether the call is read-only, whether it mutates or expires anything, or what happens when the envelope is exhausted.

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?

A single compact sentence with the primary payload (remaining envelope + per-leg status) front-loaded and the auth constraint trailing. Nothing is wasted.

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 a tool with no annotations and no output schema, the description leaves too much open: what 'remaining' is measured in (count, currency, amount), what a 'leg' is, and the shape of the response. It is a terse hint rather than a usable definition.

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 0%, so the description must compensate, and it only half does: 'token' is clarified as the operator's Bearer token, but 'envelope_id' receives no format, provenance, or sourcing guidance. An agent still does not know what an envelope_id looks like or where to obtain one.

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 resource (the remaining envelope balance) plus per-leg status, which an agent can distinguish from siblings like issue_envelope or verify_receipt. The verb is implied by the name rather than stated, so it falls short of a full verb+resource formulation.

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?

There is no statement of when to call this versus siblings such as verify_receipt or reconstruction, and no preconditions beyond the token requirement. The agent must infer that this is a post-issuance status check.

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