blockchain_fees_utxo

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

With no annotations provided, the description carries the full burden. It discloses the two actions, includes credit costs per action/blockchain, and notes that credits are indicative and actual costs are returned in response headers. This adds meaningful behavioral context beyond the schema, though it doesn't explicitly state read-only behavior or side effects.

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 front-loaded with the main purpose in the first sentence, followed by usage guidance and a structured action list. The credits section is somewhat verbose but serves a purpose (cost transparency). Overall, it's well-organized and each section earns its place, though it could be slightly more compact.

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?

The description covers the tool's scope, use cases, available actions, and cost information, which is solid for a fee-recommendation tool. It lacks an output schema but the actions imply the return type. The description is sufficiently complete given the tool's complexity, though it could clarify the meaning of fee tiers or the return structure.

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% and each parameter has a description. The tool description adds action-to-parameter mapping (e.g., feeRatePriority and confirmationTarget are 'estimate-transaction-smart-fee only') but this is also present in the schema. The description doesn't significantly augment the parameter semantics beyond what the schema already provides, so baseline 3 is appropriate.

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 the tool's purpose: 'Get fee recommendations for UTXO blockchains' and lists the specific blockchains (bitcoin, bitcoin-cash, litecoin, dogecoin, dash, zcash). It also differentiates from sibling tools by naming the UTXO scope, which contrasts with the EVM and XRP siblings.

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 description provides explicit usage context: 'Use this before preparing or signing a transaction to determine the appropriate fee rate.' It also breaks down the two actions and their specific use cases. However, it does not explicitly mention when to avoid this tool or name alternative tools, so it falls short of a 5.

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