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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the restated 'Read-only and idempotent; no side effects' sentence earns little. Beyond that, the description adds real behavioral context: the probe is a genuine liveness check rather than a fabricated reliability score, and errors return a structured error object.

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?

Purpose and usage condition are front-loaded in the first two sentences, and the concrete example at the end is genuinely useful. It is slightly padded: the read-only/idempotent sentence duplicates annotations, and 'On error, returns a structured error' is close to a tautology.

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?

An output schema exists, so return-value documentation is unnecessary, and the description covers purpose, precondition, behavior, and error handling. The only meaningful gap is not routing the agent to a sibling when the capability is not yet identified.

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%, so the schema already documents both sml_id and the probe boolean with its default. The description mentions the liveness probe but adds no syntax, format, or cost guidance beyond what the schema provides, so the baseline 3 applies.

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 names a specific verb and resource ('Inspect one live SqueezeOS capability by its sml_id') and scopes it to a single capability rather than a set. It implies differentiation from the discovery/compare siblings ('when an agent has a candidate capability'), but never names an alternative tool, so it stops short of full sibling separation.

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?

It gives a clear triggering condition: use it when a candidate capability is already in hand and its endpoint, parameters, and x402 payment terms are needed before calling. It does not, however, name the nearest alternative (e.g. read_capability or x402_contract) or state when this tool is the wrong choice.

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