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

Annotations already declare non-read-only and open-world, and the description adds genuinely new behavior: offer escrows items (custody transfer), accept performs the swap, and the 32-block proximity limit. It does not disclose what happens to escrowed items on decline, cancel, or expiry — a meaningful gap for a mutation tool handling item custody.

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?

A single sentence with the core scope first and op semantics packed into semicolon-separated clauses. Zero filler and no repetition of schema detail.

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?

For a 7-parameter mutation tool with nested item maps and no output schema, the description covers the happy path but omits escrow refund/lapse behavior, whether swaps are atomic or partially fillable, and what op=list or op=accept return. Adequate but with real gaps.

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 baseline is 3; the description adds value because the op enum itself is only documented as 'What to do.' and the prose is what actually explains each mode's effect. It still says nothing about the give/want nested item maps or how offer_id relates to a listed offer beyond what the schema states.

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 ('Trade with another agent') plus a hard scope constraint ('within 32 blocks'), then enumerates every op mode with one-clause semantics. No sibling tool (attack, chat, craft, batch) overlaps, so an agent can select this unambiguously.

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?

Each op is given its role: offer escrows, accept swaps, decline/cancel close, list enumerates. That is effective per-operation routing guidance. It stops short of explicit when-not-to-use conditions or a note on which op to pick when an offer has already lapsed.

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