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

Annotations already declare readOnly/idempotent/no-destruct, so the safety profile is covered. The description adds substantial context beyond that: it explains the "marked as given" behavior for context units, discloses exactly what is stored versus not stored (account keys only as a one-way hash, no IPs, no billing/validation sources), and notes result summarization.

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 workflow routing are front-loaded in the first two sentences, then privacy/logging details follow. The data-handling passage is long, but it is compliance-relevant rather than filler, and every sentence carries content; minor tightening would help.

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 usefully characterizes returns (the specific question categories and where each answer lives) and the chaining contract. For a two-param, read-only tool this is close to complete, though it doesn't address output size or ordering of the returned questions.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: it clarifies that units already stated in context are marked "given" and not asked again, and frames vendors as the paid-for set. That is behavior the schema's field descriptions alone don't convey as clearly.

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 states a specific resource and scope: it returns which usage numbers decide each vendor's answer (emails/month, domains, database size, seats), where the user finds each one, and ready-to-ask questions. It names the sibling tools (audit_stack, find_alternatives) it feeds, so an agent can place it precisely in the workflow.

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 explicit timing ("Before an audit") and an explicit downstream action ("Pass the answers to audit_stack or find_alternatives as usage and features_used"), which is strong routing guidance. It stops short of stating when NOT to use it or naming a competing sibling to avoid.

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