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

Annotations already cover readOnlyHint and idempotentHint, so the bar is lower, yet the description adds real behavioral context: each read is 'Built from the verified signed publication' (provenance/freshness), 'Expired observations are historical' (how stale data is presented), and it performs no payment. That is useful disclosure beyond the structured hints.

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 verb and target, then the report contents, then provenance and the no-payment guarantee. Mostly efficient; the inline URL repeats what the slash path already conveys and adds a little length without adding 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?

No parameters and an output schema exists, so return structure needn't be described, and the description still enumerates the report sections. The one gap is that it never routes the agent among the many sibling read tools when this check is or isn't the right one.

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?

Zero parameters, so there is no per-parameter semantics to explain; the baseline for a parameterless tool is 4. The description compensates by making clear the report is fixed to one specific product rather than being configurable.

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?

Specific verb ('Read') plus a concrete resource ('Agent Shopping Check for Vuori Kore Short, Ink, US'), with the report's contents enumerated (product context, advertised claims with sources, gaps, editorial fixes). An agent can tell this delivers a curated shopping-gap report rather than raw listings. It does not, however, name a sibling it should be preferred over.

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?

Usage is implied rather than stated: 'free', 'Read', and 'Never pays or starts checkout' tell the agent this is a safe pre-purchase lookup that can substitute for initiating a checkout. No explicit when-to-use trigger and no alternative sibling (check_listing, get_publication, get_evidence) is offered for cases where this check doesn't apply.

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