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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description still adds useful behavior beyond that: it requires a subscriber key, it is a snapshot 'at the last weekly check,' and it mirrors 'that week's Watch email' — clarifying cadence and data provenance/timeliness.

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 text is a run-on sentence fragment with no leading verb, and the opener 'OperStack Watch subscribers, with their key' is a confusing preamble rather than a front-loaded statement of what the tool does. The valuable content (citation results, trend, share) is buried mid-sentence.

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 read-only, single-parameter tool with no output schema, the description does describe the returned content (citation status, weekly trend, competitor share) and its source. It still lacks a clean action statement and any routing guidance, which an agent needs to choose it over visually similar siblings.

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 description coverage is 100% and the single 'site' parameter is fully documented in the schema ('Only if you watch more than one site'). The description adds nothing about the parameter, so the baseline 3 applies.

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 names a specific deliverable: whether ChatGPT/Perplexity cited the subscriber in their 10 buyer questions, the week-by-week trend, and share vs competitors. That is concrete enough to tell what the tool returns. It does not, however, contrast itself with overlapping siblings such as who_instead or ai_visits, so differentiation is left to inference.

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?

There is no explicit when-to-use or when-not-to-use guidance and no named alternatives. The only contextual cue is the implied 'OperStack Watch subscribers, with their key' prerequisite, which hints at an audience/auth requirement but not when to call this over siblings like what_changed or who_instead.

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