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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is fully covered by structured data. The description adds the scope distinction (aggregate vs per-agent) but says nothing extra about freshness, sampling, or data sources beyond annotations, and itemizing returned fields is partly redundant with the output schema.

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?

Two sentences: the first front-loads what is returned, the second handles routing to alternatives. No filler, no repetition of the title, and the most decision-relevant information comes first.

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?

Zero parameters, an output schema that documents return values, and annotations that carry the safety profile mean the description only needed to supply scope and routing — which it does. Nothing an agent needs before calling this zero-arg read is missing.

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?

The tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. Nothing in the description misleads about inputs, and the absence of arguments is consistent with the empty schema.

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 ('ERC-8004 ReputationRegistry aggregate') and enumerates the returned metrics: feedback count, agents with reputation, unique reviewers, average score. It also explicitly contrasts itself with the per-agent siblings get_trust_forensics and check_agent_trust, so an agent can pick it without opening a schema.

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?

Gives a positive usage cue ('use it for market context') and a negative one plus alternatives ('per-agent answers come from get_trust_forensics or check_agent_trust'). The routing condition between aggregate and per-agent views is unambiguous.

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