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

Annotations establish write semantics (readOnlyHint=false, destructiveHint=false, openWorldHint=false); the description usefully adds the auth mechanism (X-API-Key header) and the side effect of sealing the registration into an immutable evidence chain, which an agent should know before calling. It stops short of describing failure modes, key-rejection behavior, or idempotency on repeat registration.

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?

Front-loaded with the action and result, then the prerequisite, then the fallback — a sensible order for an agent scanning for callability. There is mild redundancy between 'under an API key you already hold' and the later header requirement, but nothing that obscures the meaning.

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?

Covers the essential things for a two-parameter registration call: what it does, what it returns, what credential it needs, and where to go without one. With no output schema present, the description does name the key return value (agent_id), though it could say more about the rest of the response payload or what happens on duplicate registration.

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 100%, so both parameters are already documented in the schema; the baseline of 3 applies. The description adds no extra detail about agent_name uniqueness constraints or builder_contact format beyond what the schema fields already say.

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 and resource ('Register an agent for ProveCart Verified Agent certification') plus the key outcome ('returns the public agent_id and seals the registration into the evidence chain'). It also distinguishes itself from the closest sibling by naming provecart_agent_signup as the different path.

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?

Gives an explicit precondition (caller must already hold an API key, integrator or scoped) and an explicit alternative for the case where that precondition fails ('If you have no key at all, call provecart_agent_signup instead'). The branching condition is unambiguous.

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