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

With no annotations, the description carries the full burden and does well: it discloses read-only behavior, pricing ($0.01 per call in USDC on Base), payment mechanism (x402 in params._meta["x402/payment"]), batch limit (25 tokens), free pages, and the HTTP endpoint. It stops short of error handling, rate limits, or auth failure behavior, but covers key operational traits.

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 description is a run-on collection of capabilities, pricing details, and endpoint info without clear hierarchy. Key routing information (when to use, how to choose among operations) is absent or buried. It is not excessively long, but the structure does not front-load decision-critical guidance.

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 complex tool with five parameters, multiple operation modes, no output schema, and no annotations, the description omits crucial context: how the parameters map to distinct endpoints, what the response formats look like, and how to handle payment failures. It gives pricing but not enough operational guidance for reliable invocation.

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 80%, so the schema already documents most parameters. The description adds a batch-size limit ('up to 25 tokens') and context that parameters map to specific endpoints (/tx, /block, /batch), but this largely duplicates the schema's own hints. Baseline 3 applies when the schema does the heavy lifting.

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 clearly states a verb and resource: 'Read-only Base and Ethereum chain data over x402' and enumerates specific data types (gas, blocks, balances, etc.). However, it does not differentiate this tool from the many specific chainread__ siblings (gas, balance, block, tx, etc.), leaving ambiguity about when to choose this multi-purpose tool over the focused ones.

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 on when to use this tool versus alternatives. The description lists capabilities but never states prerequisites, exclusions, or which sibling tool to pick for a given task. The only hint is 'Free /scan and /t/<address> verdict pages', but this does not help an agent choose between this and chainread__verdict or others.

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