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

Annotations only declare readOnlyHint=false and destructiveHint=false. The description goes beyond that by disclosing what happens when `operator` is omitted (recorded as the zero address / 'Unknown') and the downstream consequence that prove cannot match the caller. This is genuine behavioral context an agent could not get from annotations alone.

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 compact sentences, with the core action front-loaded and the operator caveat as the payoff. The trailing clause 'and prove cannot match it to you' is slightly awkward but carries real information, so the length is justified.

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 7-parameter write tool with a nested operator object and no output schema, the description covers the action, the critical optional parameter, and its failure mode. It omits what a successful registration returns and how it relates to the subsequent prove/activate steps, which would round it 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 coverage is 100%, so baseline is 3, but the description adds value beyond the schema by explaining the practical effect of the optional `operator` object (zero-address fallback and proof-matching failure), which the schema only hints at. The remaining six parameters get no description-level treatment, so it is not a 5.

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+resource: 'Register a new machine on the PCC network.' This is clearly distinct from the read sibling 'get_registration' and the follow-up 'prove_registration'/'activate_registration'. It doesn't explicitly name those siblings, so it stops short of a 5.

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 description implies this is the entry point of the registration flow and gives conditional guidance on the `operator` field, but it never states when to use this tool versus the adjacent registration steps (prove_registration, activate_registration, list_registrations). Usage is implied rather than spelled out.

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