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

With no annotations, the description carries the full burden and does well: it discloses 'No auth', warns the band is a 'shadow heuristic' that is 'informational, not a risk-tier contribution, until it clears the precision gate', and explains how expired Permit2 sub-allowances are labeled. It omits any statement about result size/pagination, which keeps it from a 5.

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 resource and the headline risk signal, and each sentence carries information. It is dense with internal jargon ('shadow heuristic', 'precision gate') that mildly taxes readability.

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 output schema exists, so the description must describe returns; it does cover row semantics and the approval-risk band, plus the single-chain caveat delegated to the schema. It stops short of explaining pagination or result volume.

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%, so the schema already documents the chain and address parameters in depth (spellings, defaults, per-chain behavior). The description adds no meaning beyond that, so the baseline 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: 'Open ERC-20/Permit2 allowances for an address' with decoded facts, which is clearly distinct from the risk/compliance/exposure siblings by resource type. It does not explicitly name a sibling to contrast against, so it stops short of a 5.

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?

Provides interpretive guidance for the returned data (what an unlimited-to-unknown spender means, what a known-service spender looks like) but never states when to choose this tool versus get_address_risk or get_address_exposure. Usage is implied rather than directed.

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