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

Goes well beyond the annotations: discloses pricing ($0.01/call via x402 USDC or card key), first 25 free, failed calls free, 404 uncharged for a nonexistent mint, no caching (repeats are not free), and that the holder lookup is best-effort due to public node rate limits. Annotations already cover read-only/non-destructive, and the description adds substantive operational context.

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 verb, resource and returned fields, and the safety/usage note follows immediately. The closing sentence ('each call is charged, so repeats are not free') partially restates the pricing already given, a minor redundancy.

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 carries the return-value burden and does so by enumerating every returned field plus the optional holders list. Error behavior (404 uncharged) and rate-limit caveat round out what an agent needs to call this correctly.

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%, so baseline is 3, but the description adds value: a concrete example mint address and the framing of `holders` as 'largest holder accounts with their share of supply' on request, which clarifies the intent of the optional param beyond the schema's terse wording.

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 ('look up a Solana SPL token by its mint address') and enumerates exactly what is returned: decimals, supply, mint/freeze authority, token program, optional top holders. This clearly separates it from siblings like solana_balance (native SOL balance) or the EVM *_token_info tools.

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?

Gives an explicit use case: 'Use before buying or accepting an unknown Solana token.' It does not name a specific sibling alternative or a when-not-to-use condition, but the trigger context is unambiguous for an agent.

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