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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds valuable behavioral context beyond that: it describes the return structure (per-row breakdown plus summary with count, avgTrustScore, and issuer types) and the graceful degradation to an empty envelope on missing data, which is not evident from annotations.

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 front-loaded with the main purpose and contains four sentences, each serving a distinct role: core function, mode differentiation, return value, and usage context. It is concise without being terse, though it could tighten the use-case sentence slightly.

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?

The description covers the tool's purpose, modes, return value, graceful degradation, and typical use cases. Since there is no output schema, the description's mention of the summary fields (count, avgTrustScore, issuer types) is helpful. Missing 'limit' semantics is a minor gap, but overall the description is sufficiently complete for a read-only query tool.

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 the 'mode' parameter thoroughly (subject = ABOUT this entity, issuer = BY this entity) and implies 'rootUid' is the entity identifier via context. However, it does not explain the 'limit' parameter's meaning or behavior, leaving a notable gap.

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 identifies the tool's function with a specific verb and resource: 'Resolve EAS Schema D (cross-attestation) peer-trust rows for a given entity.' The two modes (subject/issuer) further differentiate it from sibling verification tools by explaining both the incoming and outgoing attestation perspectives.

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 provides explicit usage context: 'Use this in trust-graph composition flows' and gives concrete examples such as 'buyer-agent verifying a merchant has lender testimonials, lender-agent reading peer signals.' However, it does not explicitly name alternatives or state when not to use this tool, so it stops short of a 5.

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