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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behaviour, so the safety profile is covered. The description adds information the annotations do not: zero authentication ('no key needed') and no metering cost, which materially affects whether an agent should hesitate before calling.

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?

Two tight sentences: the payload description is front-loaded, followed by the cost/auth reassurance and then the usage trigger. Nothing is redundant and nothing is missing.

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?

With no parameters, no output schema, and full annotation coverage, the description carries little burden. It names the returned fields (bundle, price) and the access conditions, though it stops short of describing ordering, plan tiers, or response shape in any detail.

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 the baseline is 4. The description correctly implies a no-argument, whole-catalogue call and adds no misleading parameter cues.

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 what the tool returns: every plan's monthly check bundle and draft price, framed as 'the ProofMart menu'. The verb 'list' comes from the name rather than the text, but the resource and payload are unmistakable and the unrelated sibling (verify_claim) needs no explicit differentiation.

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?

'Useful when an owner asks what subscribing would get them' supplies a concrete triggering situation. There are no exclusions or named alternatives, but with only one sibling (verify_claim) that does something entirely different, no routing ambiguity exists.

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