accounts / positions

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the single-token vs. portfolio scope constraint, but says nothing about return shape, decimal normalization, or behaviour for unknown tokens, which is the remaining burden for a balance read.

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 front-loaded sentence with no filler; the scope qualifier is placed where it matters. It is telegraphic to the point of being slightly ambiguous ('explicitly named' by what key?), but every word earns its place.

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?

With no output schema, the description should convey what comes back (raw amount, decimals-adjusted, symbol/decimals metadata) and it does not. Annotations cover safety, and the token-type hint helps, but the return contract and chain_id semantics remain gaps for a 3-parameter read tool.

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 0% across three required parameters. The description clarifies only that 'token' may be an ERC20 or LP token, which is genuinely useful; it says nothing about 'wallet' (address format?) or 'chain_id' (which networks, numeric IDs vs. names?), leaving two parameters undocumented everywhere.

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: reads the balance of an explicitly named token for a wallet. The phrase 'not full portfolio' scopes it against the broader sibling accounts.balances without naming it, so an agent can reasonably distinguish the two, though it stops short of an explicit sibling reference.

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?

'not full portfolio' implies when to prefer this over a portfolio-wide read, but the guidance is negative scoping only. It never names accounts.balances as the alternative, nor states what happens if the token is not held or if an unsupported token type is passed.

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