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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavior: it is free, it returns a coarse band rather than a precise score, and the full data sits behind a paid sibling. It does not mention rate limits or whether a free-tier quota exists, which is the main residual gap.

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?

Three short sentences: what it is, what it omits, where to go for the full version. The most decision-relevant facts (free, coarse output) are front-loaded and nothing is repeated from the schema or annotations.

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?

There is no output schema, and the description compensates by naming the return shape (verdict, score band, flag codes) and its limitations. Combined with the fully documented two-parameter schema, an agent has everything needed to call it and interpret the result.

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 100% and both parameters (chain with default 8453/Base, agent_id as ERC-8004 Identity Registry token id) are documented in the schema itself. The description adds no syntax, format or validation detail beyond that, so the baseline of 3 applies.

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 ("Vista GRATUITA de due diligence de un agente ERC-8004") and immediately enumerates what the response contains: verdict usable/caution/avoid, score band and flag codes. It also draws an explicit line against the sibling agent_check, so an agent can distinguish the two without opening either 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 both sides of the routing decision: this tool is the free preview, and "Para el reporte completo usa agent_check (0.02 USDC)" names the alternative together with its cost. The list of excluded fields (exact score, services, metadata, reputation, wallet) makes the escalation condition concrete rather than inferred.

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