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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the description's main additions are the upstream source (mempool.space public API), the cost profile ('Price: free'), and the error contract (isError with message, not charged). These are genuinely useful beyond the annotations, though rate limits or caching behavior are unstated.

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 resource and returned fields, then terse 'Price:' and 'Errors:' clauses. Dense and waste-free, though the fragment style is slightly clipped and the returned-field list partly duplicates the output schema.

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 an output schema present, return values need not be described, yet the description adds source, cost, and error handling — enough for an agent to select and call a zero-param read safely. Only the absence of usage routing against sibling network tools is a gap.

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 tool takes zero parameters, so the baseline is 4. The description correctly offers no parameter guidance and instead spends its words on return content, which is the right allocation here.

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 resource (Bitcoin network status) and enumerates exactly what it returns: fee rates, mempool size, block height, difficulty adjustment, hashrate. The chain-specific framing clearly separates it from siblings like solana_network and gas_now.

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 'Bitcoin right now' framing implies a live-snapshot use case, but there is no explicit when-to-use or when-not, and no sibling is named as an alternative. An agent must infer that this is the Bitcoin counterpart to solana_network.

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