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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states what is returned (size, fee floor, congestion summary) but does not disclose data freshness, caching behavior, potential cost or latency, or any additional traits beyond the purpose. For a simple stats tool, this is minimal transparency.

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, front-loaded sentence that directly states what the tool does without any filler. Every word contributes to the purpose, achieving high conciseness and clarity.

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 that the tool has no parameters and an output schema exists, the description need not detail return values. It covers the key aspects of the tool (size, fee floor, congestion) sufficiently for a zero-parameter snapshot. The only minor gap is that 'congestion summary' is somewhat vague, but the output schema should clarify this.

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 has zero parameters, so schema coverage is trivially complete and there is no need to document parameter meanings. The baseline for zero parameters is 4, and the description adds no unnecessary parameter details.

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 uses a specific verb ('Return') and clearly identifies the resource: current Bitcoin mempool size, fee floor, and congestion summary. It distinguishes from siblings like fees_recommended or mempool_tx by focusing on aggregate stats rather than specific fee levels or transactions.

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?

Usage context is implied but not explicitly stated. The description indicates this tool provides a current mempool snapshot, suggesting it should be used when an overall mempool overview is needed rather than fee recommendations or individual transaction data. However, no explicit 'when not to use' or comparison with alternatives is provided.

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