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

With readOnlyHint=false and destructiveHint=false already declaring a non-destructive write, the description adds genuinely new context: reads cost 1 unit, linking writes, signatures are personal_sign with ERC-1271 contract-wallet support, a keeper posts reputation after linking, and three concrete error cases are enumerated. It omits what happens when re-calling with an already-linked identity (idempotency/reversibility of a link), a meaningful gap for a write tool.

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?

One dense block with several run-on sentences mixing purpose, registry addresses, mode routing, economics, side effects, return shape, and errors. It is front-loaded and has no filler, but the mode-conditional behavior would be far more scannable as separated clauses; agents must parse a paragraph to find the branch they need.

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, and the description compensates by enumerating the return shape (name, identity{...} or null, reputation{pnl, upvotes}, and conditionally register{tx}/link{message}). Combined with error cases and cost, an agent has enough to call and interpret results; it lacks only post-link lifecycle details (unlink, repeat-linking).

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 coverage is 100%, so the 3 baseline applies, but the description earns more: it specifies that the two parameters are co-required ("With agentId and signature: links"), that the signature is the owner's over the exact text this tool returns (not arbitrary text), and that ERC-1271 counts. That linkage — signature depends on a prior call's output — is not derivable from the 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?

The first sentence states a specific resource ("The caller's ERC-8004 identity ... and what LoomDesk has posted about it"), and the description then names its three modes: read state, emit an unsigned registration tx, or link an identity. Sibling differentiation is only partial — it references agent_grant for the grant but doesn't distinguish itself from agent_quota or the arena_* family. Heavy jargon (ERC-8004, keeper, loomdesk/pnl) slows comprehension but the verb+resource is unambiguous.

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?

Usage is routed explicitly by parameter shape — "With no fields: ..." versus "With agentId and signature: links that identity to this key" — which tells the agent exactly which mode fires. It also flags a downstream sibling ("the agent may earn the grant (agent_grant)"). No explicit when-not-to-use exclusions are given, 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.