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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is covered. The description adds behavioral value by disclosing the returned fields (including a 'congestion verdict') and what the tool is meant to answer, though it does not discuss caching, refresh cadence, or data staleness.

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, then the usage guidance, then the return fields — a logical order with no filler sentences. The trailing field list is slightly dense but every item is informative given there is no 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 no output schema and no parameters, the description compensates by enumerating the return fields and giving a practical interpretation of them. Nothing an agent needs to select or invoke this tool is missing.

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 and no parameter documentation is required. The description correctly adds no param detail and instead spends its budget on return semantics.

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 verb+resource (Monero mempool state) and enumerates the exact measurements returned: pending tx count, bytes, fees, oldest tx age, double-spend/failing counts. This is clearly distinguishable from siblings like xmr_get_network_stats, xmr_get_fee_rates, or xmr_get_transaction.

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?

Includes explicit 'When to use' (is the network congested, how long will a new tx wait) and 'Do not use' clauses that name the correct alternatives (xmr_get_fee_rates for fees, xmr_get_transaction for a specific payment). Routing is unambiguous.

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