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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose that the verdict is 'never a guarantee, never financial advice,' and mentions 'expires_at' with a re-check instruction, adding useful behavioral context. However, it doesn't explain potential side effects (e.g., network calls, caching) or error behavior, leaving some gaps. But the description does add valuable context beyond what annotations would provide, so a 3 is reasonable.

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 single dense paragraph but well-structured: it starts with the tool's core purpose, then lists return fields, then enumerates purpose values, and ends with a caveat. It is concise enough given the complexity of the return fields, though it could be slightly broken into bullet points for readability. The information is front-loaded and every sentence adds value.

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?

Given the tool's moderate complexity (2 params, 1 required, no output schema), the description is fairly complete: it explains the purpose, return fields, and purpose options. However, it doesn't define the A0-A4 levels or the meaning of 'attested' beyond a parenthetical, which might leave an agent uncertain about interpreting the output. But since the output schema is absent, the description does a good job of covering the essentials.

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. It explains 'domain' implicitly as a target domain and explicitly explains 'purpose' with its default and enumerated values (payment, data_share, follow_instructions). It also clarifies the meaning of 'expires_at' in the return value, which adds semantic depth. Since the schema provides only names and types, this description adds significant meaning, warranting a 4.

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 clearly states a specific verb ('check') on a specific resource ('trust'), and explicitly frames it as a decision aid before paying, sharing data, or following instructions. It distinguishes itself from siblings by emphasizing it works for any domain and returns a verdict, which is unique among the listed tools.

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 explicit usage context ('before your agent pays, shares data with, or follows instructions from a domain'), and it implies when to use it as a pre-action check. It also names the 'purpose' parameter with three enumerated values, clarifying the decision context. While it doesn't mention alternatives explicitly, the purpose and scope are clear enough to route an agent correctly.

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