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

Annotations already flag destructiveHint=true and idempotentHint=false; the description adds real context beyond them — the owner check that gates the operation and the fact that weights renormalise after a change. That renormalisation note is exactly the kind of side effect an agent needs. It omits rollback/reversibility details, keeping it short of 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 action and scope, which is good, but the api_key requirement is stated twice in two slightly different phrasings ('Needs your api_key…' and '(needs your linked account's key)'). That duplication wastes part of an already tiny description.

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 destructive mutation with no output schema and low schema coverage, the description covers the key behavioral risk (owner scoping, renormalisation) but leaves parameter meanings and success/failure response implied. Adequate, not complete.

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 only 25% — only api_key is documented in the schema, so basket_id, symbol, and the action enum are unexplained in both places. The description names no parameter semantics at all (e.g. what basket_id refers to, whether symbol must already exist), so it fails to compensate for the coverage gap.

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?

A specific verb pair ('add or remove') plus a specific resource ('an asset on the signed-in user's OWN basket vehicle') with a scope qualifier (owner-checked). It's clearly distinguishable from read-oriented siblings like theme_journey_basket and theme_journey_my_baskets, though neither is named.

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?

The parenthetical '(register_agent, no key needed)' implies the auth prerequisite for newcomers, but there's no explicit when-to-use vs when-not, and no pointer to the sibling that lists baskets or previews them. Usage is inferable rather than stated.

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