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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds context annotations cannot express: that the call is free, that it is a cached read rather than a fresh check, and what the receipt payload contains. It does not mention pagination or failure modes, but for a read-only lookup that is minor.

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?

Dense but front-loaded: the core action and 'Free' lead, followed by parameter guidance, then the payload, then the exclusion. Every sentence carries information, though the return-field list makes it run a bit long.

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?

No output schema exists, so the description compensates by enumerating the returned fields (listing URL, terms, verdict, reason, reason_code, confidence, history, timestamp, badge snippets). Both parameters are explained and the alternative tool is named, leaving nothing an agent needs to call it correctly.

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 the baseline is 3, but the description goes beyond the terse schema by explaining the id format (sc-... from endpoint_spot_check's receipt_id, or a 10-hex crawl id) and what url selects (latest live plus crawl receipt). That provenance and format detail is genuine added value over 'receipt id'.

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 ('read a public 402xAgent receipt') and immediately scopes it as free and read-only. It distinguishes itself from the sibling that performs checks by explicitly naming endpoint_spot_check as the tool that does fresh checks.

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?

Explicitly covers both invocation modes (id vs url) and what each returns, and gives the exclusion: 'Does not run a fresh check (use endpoint_spot_check for that).' This is exactly the when/when-not/alternative guidance the dimension asks for.

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