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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description does not need to repeat safety. It does add some behavioral context: the tool returns a signed receipt containing 'verified' and 'decision', and the access notes (public, no email, no API key) hint at authentication requirements. However, this context is disorganized and not fully fleshed out, so a 3 is appropriate.

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?

The description is a long run-on string mixing unrelated pricing details ('Buy looks_20 pack ($0.20) or look $0.10. Stamp ticket $0.05.') with operational instructions. The core purpose is not front-loaded, and each sentence is not earning its place. It is verbose without being informative.

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 two parameters and no output schema, the description leaves critical gaps: it does not explain what 'id' is for, does not describe the full return structure, and does not distinguish this tool from siblings like meter_scan or meter_stamp. The provided decision logic is helpful but the overall context is inadequate for correct invocation.

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 0%, so the description must compensate for both parameters. It explicitly mentions 'by stamp_id', giving some meaning to that parameter, but it never mentions the 'id' parameter at all. The description is not structured as a parameter reference and leaves half the inputs unexplained.

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 title says 'Verify a Meter stamp', but the description never plainly states that the tool verifies a stamp. The closest action phrases are 'GET a signed allow|stop receipt by stamp_id' and the opening question 'Can I pay this address?', both buried among pricing and policy statements. It does not clearly differentiate this from siblings like meter_scan or meter_stamp.

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 gives some usage context ('before you accept agent USDC') and a decision rule for interpreting output, but it provides no guidance on when to use this tool versus alternatives, nor does it name any sibling tools or exclusions. The 'No inbox', 'No email', and 'No API key' notes are access constraints, not usage routing.

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