health_check

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

Annotations already indicate readOnly/idempotent, but the description adds critical behavioral details: lazy cache initialization causing 10-60 second delays on first call, and explains the cache_integrity and cache_ready fields, going beyond what annotations alone convey.

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 well-structured: first sentence gives purpose, then two paragraphs cover usage and return values. It is slightly lengthy but every sentence adds value; no redundancy.

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 no parameters, a rich output schema (implied by return description), and annotations covering safety, the description fully explains behavior, usage scenarios, and output fields, including multi-user mode details. No gaps remain.

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?

With zero parameters, baseline is 4. The description has no need to add parameter details since the input schema is empty; the tool's purpose is sufficiently explained without parameter documentation.

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 clearly states the tool checks server health, API key configuration, and cache readiness. It distinguishes from siblings like cache_status by specifying it should be called before detect_* or cache_status, positioning it as a preliminary readiness check.

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?

Provides explicit guidance: call at session start before detect_* or cache_status, and after a time-out to distinguish transient loading delays from permanent failures. It covers both when to use and how to interpret results.

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