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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the bar for additional disclosure is lower. The description adds meaningful behavioral detail beyond annotations: it does not dial the endpoint, it returns null when Kawal has never called it, and it describes the protocol-answer filtering and latency metrics. No contradiction with annotations.

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?

Two dense sentences with zero filler. The main operation and return content are front-loaded, and the second sentence efficiently captures the negative case and the relationship to verify_agent. Every sentence earns its place.

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?

There is no output schema, so the description correctly carries the burden of explaining return values: call counts, protocol-valid responses, start time, median and worst latency, and null when absent. It also clarifies the 'without dialling' side effect and names the action that creates the first record. The tool is fully understandable for a correct call without looking elsewhere.

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 description coverage is 100%, with both chainId and tokenId already documented concretely ('Chain id. One of 56, 97. Defaults to 56.' and 'ERC-8004 token id, decimal digits.'). The description does not add parameter-level detail, but it does not need to; the baseline of 3 applies because the schema carries the full burden.

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 opens with a specific verb+resource: 'Read the history Kawal keeps of one agent's endpoint' and immediately enumerates the exact metrics returned (call count, protocol-valid answers, first-call time, median and worst latency). It also distinguishes itself from the registry and from verify_agent, making sibling differentiation clear.

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 clearly frames when to use this tool: when you need Kawal's observed probe history rather than the registry record. It also calls out the null case when Kawal has never probed the endpoint and names verify_agent as the action that makes the first call, effectively pointing to the relevant alternative. However, it stops short of an explicit 'use A instead of B' rule for all siblings.

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