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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower, and the description adds genuinely non-derivable behavior: the token is single-use and expires after 15 minutes. Those traits directly affect how an agent must sequence and retry calls. It does not say whether issuance is rate-limited or whether repeated calls invalidate prior tokens.

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 sentence that front-loads what is returned, then the expiry, then the consumer. Every clause carries information an agent needs; there is 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?

For a parameterless, annotation-backed step in a registration flow, the description covers what the agent needs: what comes back, how long it lives, and who needs it. With no output schema present, the description could go slightly further on how the token is surfaced in the response, but the essential facts are all present.

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?

The tool takes zero parameters, so there are no semantics to document and no schema coverage gap; the baseline of 4 applies.

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?

Specific verb+resource with the artifact characterized: a single-use proof-of-work token with a stated 15-minute lifetime. It also names the sibling that consumes it (register_agent), so an agent can distinguish it from registration-adjacent tools like get_status or register_agent itself.

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?

"needed by register_agent" clearly establishes the usage context — this is the prerequisite step before registration. It stops short of an explicit when/when-not directive (e.g., that calling register_agent without it will fail, or that a stale token must be re-fetched), but the routing intent is unambiguous.

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