check_health_access

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description adds real value by naming the three diagnostics produced and by framing it as a prerequisite troubleshooting step. It does not discuss latency, throttling, or what a partial failure looks like, so it stops short of 5.

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 one-sentence purpose, followed by the enumerated outputs and a conditional usage rule — a sensible order. The three example prompts are slightly redundant padding given the already-explicit trigger condition, but they aid selection rather than obscure it.

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 no explanation, and the description still summarizes what the diagnostic reports. For a zero-argument, read-only diagnostic, nothing an agent needs in order to decide to call it and interpret the outcome 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 no parameters, so the baseline is 4 and there is nothing the description could clarify about inputs. The absence of arguments is itself implied by the 'run this first' framing, requiring no credentials or identifiers from the caller.

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?

Opens with a specific verb+resource: 'Diagnose whether this server can actually reach the AWS Health API', and the three reported facts (calling identity, support-plan access, org view) scope it precisely. Every sibling tool is a data-retrieval tool, so a connectivity/permission diagnostic is unambiguously distinct.

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?

'Run this first when other tools return access errors' gives an explicit trigger condition that routes the agent away from the get_*/list_* siblings when a failure occurs. The example prompts reinforce the activation context (permission problems, misconfiguration, org-wide access questions).

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