blockBlock details by hash or height.
| Name | Required | Description | Default |
|---|---|---|---|
| chain | Yes | ||
| hash_or_height | Yes | Block hash (hex) or numeric height as string. |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "chain": "bitcoin",
+ "hash_or_height": "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"
+ },
+ {
+ "chain": "ethereum",
+ "hash_or_height": "19000000"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Block details including hash, height, transactions, and metadata",
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds the detail that lookup is by hash or height, which is more about input semantics than behavior. It does not disclose what 'details' specifically include, but with annotations covering the safety profile, the description provides acceptable incremental value.
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 single short sentence that directly states the tool's function. It is front-loaded and every word earns its place, with no fluff or 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?
Given the low complexity, existing output schema, and annotations, the description is minimally viable but still incomplete. It lacks usage guidelines and does not explain the chain parameter, which an agent needs to correctly invoke the tool. It is adequate for a simple lookup but leaves clear gaps.
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 only 50%: only hash_or_height has a description, while chain is undocumented. The tool description repeats the hash-or-height concept already present in the schema and offers no clarification for the chain parameter. It fails to compensate for the missing schema description on chain.
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 'Block details by hash or height' clearly identifies the resource (block) and the two primary lookup methods. It distinguishes itself from sibling tools like transaction and address by specifying hash or height lookup, though it lacks an explicit verb like 'Get' or 'Fetch'.
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 provided on when to use this tool versus alternatives such as transaction or address. The description does not mention any context, exclusions, or alternative tools, leaving the agent to infer appropriate usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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