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

Annotations already declare this is a safe, idempotent read. The description adds genuinely new context: on failure the tool still returns a structured error object containing error.code, error.http_status, error.retry_recommended, and error.retry_after_seconds, which tells the agent how failures are surfaced and how to back off. Not a full 5 since rate limits and caching TTL of the status result are unstated.

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?

Three short sentences with the core purpose front-loaded and the error shape second. The enumerated error fields are slightly list-heavy but each maps to a behavior an agent needs to react correctly.

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?

For a zero-param, read-only status endpoint this covers purpose, success payload nature ('health and discovery metadata'), and failure shape. Since an output schema exists the return values needn't be spelled out, so remaining gaps (e.g. payload structure details) are acceptable.

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 there is nothing to document; a baseline 4 applies. The description correctly avoids redundant parameter chatter.

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 and resource ('Check whether the Pricewatcha public API is available') and scopes it to the public API rather than job/watch status. Distinguishes it from siblings like get_job_status and get_watch_status by naming the target of the 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?

The health-check framing implies when to use it (availability probing), and the retry fields hint at a pre-retry check pattern, but the description never states when to call it versus alternatives or any prerequisites. Usage is inferred rather than explicit.

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