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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds value beyond that: it discloses the live data source ('public Solana JSON-RPC (getBalance)') and that a slot is returned, indicating freshness/snapshot semantics.

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?

Three short sentences with zero filler. Resource and units are front-loaded, followed by the natural-language intent, then provenance. Every sentence 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?

Even without an output schema, the description enumerates the return contents (lamports, SOL, slot read at), so an agent knows what it will get. For a single-parameter, read-only lookup, nothing material is missing.

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% for the single 'wallet' parameter, including base58 format and length constraints, so the schema carries the burden. The description adds no format or syntax detail beyond it. Baseline 3 applies.

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 resource and scope: 'Native SOL balance of a Solana address'. The word 'native' implicitly carves it out from sibling solana_wallet_tokens (SPL token balances), and the rephrased natural-language prompt clarifies the exact agent question it answers.

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 line 'Answers "how much SOL does this address hold"' gives an implied usage context, but there is no explicit when-to-use guidance, no exclusions, and no named alternative (e.g. solana_wallet_tokens for non-native assets). Adequate but leaves routing partly to inference.

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