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

The description adds useful behavior beyond the annotations: this is a simulated/paper account ('pretend eth'), valuations are computed for the current block, and a key is required. The readOnly/idempotent annotations already cover the safety profile, so the added auth and simulation context earns high but not full credit.

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?

The definition is short and front-loads the account's contents before the key requirement. It is slightly telegraphic ('pretend eth left') and the lack of a verb makes it harder to parse, but no sentence is wasted.

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 zero-parameter read-only tool with no output schema, the description covers the key returned values and the access prerequisite. A slightly clearer statement of what is returned and an explicit read-only framing would make it fully 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?

The input schema has zero properties, and the 100% schema coverage makes parameter documentation unnecessary. Baseline for zero-parameter tools is 4; the description adds no conflicting parameter expectations.

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 description defines the tool as the practice account for this mite and enumerates the exact data returned: paper ETH balance, held positions, per-position sell value for the block, and weekly profit. It is clear about the resource and contents, though it lacks an explicit verb such as 'get' or 'show' and does not contrast itself with practice_trades.

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?

No guidance is given about when to call this tool instead of practice_buy, practice_sell, or practice_trades. The only operational note is that a key is required, with a docs link, which is a prerequisite rather than a selection criterion.

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