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

Although no annotations are provided, the description discloses key behavioral traits: BTC uses a node fee estimator, ZEC returns a protocol rule (ZIP-317 conventional fee), and chains without an estimator explicitly say so instead of guessing. This adds valuable transparency about the tool's behavior and limitations, which is beyond a simple read-only operation hint.

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 concise, front-loaded with the core purpose, and every sentence adds value. It efficiently covers the different chain behaviors and the usage trigger without redundancy. No wasted words.

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 tool with a single parameter and no output schema, the description is complete. It provides enough information for an agent to call it correctly: it knows the input chain, the expected output (fast/medium/slow plus mempool minimum), and how different chains behave. No critical gaps remain.

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?

The input schema already documents the 'chain' parameter with an enum and a description. The description adds value by explaining the meaning of the parameter in context: it determines the chain's fee estimation method (e.g., BTC's estimator vs. ZEC's protocol rule). With 100% schema coverage, the baseline is 3, but the description goes slightly beyond by clarifying chain-specific behavior.

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: providing fee recommendation tiers (fast/medium/slow plus mempool minimum) for a chain. It specifies the resource (fee rates) and the action (get/recommend), and distinguishes itself from siblings by noting the per-chain computation methods. It is clear what the tool does and how it differs from other fee-related tools like btc_fee_estimates.

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 explicitly states when to use the tool: when an autonomous agent is about to send a transaction and must pick a fee. It provides clear context but does not explicitly name alternative tools or state when not to use it, though the context is enough to guide selection among siblings like btc_fee_estimates.

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