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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds real value beyond that by disclosing the deterministic/read-only nature of the preflight scope and that the response is bounded metadata about stage, production availability and payment status. No auth or rate-limit detail, but not needed here.

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 sentences, front-loaded with purpose, then constraints, then the return contents. It is slightly dense but each sentence carries distinct information; nothing is redundant with the name or annotations.

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 no output schema, the description compensates by enumerating the returned fields (product, stage, deterministic flag, payment_enabled, production_enabled, supported scope, payment scope). For a zero-param informational tool this is complete enough to call correctly.

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 for the description to disambiguate; baseline 4 applies. The description correctly focuses on what the call returns rather than inventing input semantics.

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 ('Return bounded service metadata for HMI Import Preflight') and immediately differentiates from the sibling by scope: metadata discovery vs. CSV inspection. An agent can tell it apart from check_hmi_import_csv without opening either schema.

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?

Explicitly says when to use it ('only to discover the service's deployment stage, deterministic/read-only preflight scope, production availability and payment status') and when not to ('do not use it to inspect CSV content'), which routes the agent to the sibling for CSV work.

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