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

Beyond the readOnly/idempotent annotations it discloses charge semantics (unknown account charged, bad-id 422 and failed RPC 503 not charged), the fact that pool delegations are excluded from locked_near, untrusted-string handling, finality/RPC, latency, price and a per-IP free quota. This is unusually rich behavioral context that the annotations alone would not convey.

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?

Purpose and scope are front-loaded before the operational and error details, and virtually every sentence carries distinct information. It is dense and long, with slight redundancy between the opening summary and the 'Returns a NEAR account's...' clause, keeping it off a perfect 5.

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?

Despite an output schema existing, the description covers what an agent needs to call it correctly: error outcomes, charging behavior, latency, pricing, rate limits, and the security caveat about untrusted on-chain strings. Nothing material is left for the agent to infer.

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 100%, so the format of account_id is already documented. The description still adds meaning about how inputs are interpreted: an unknown account yields exists=false (and is charged) while a syntactically bad id is a 422, which goes beyond the schema's format contract.

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?

Specific verb + resource ('Get a NEAR account') with the exact returned fields enumerated (balance, staked NEAR, storage, access keys, contract deployed). It explicitly distinguishes itself from the EVM path by routing to get_portfolio, and the sibling list contains no other NEAR-account tool, so scope 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?

It names an explicit alternative with the selecting condition ('For EVM balances use get_portfolio') and notes the boundary 'no history'. It does not name a tool to use for historical data or state further when-not conditions, so it stops short of a full 5.

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