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

Annotations only say it is a non-read-only, non-destructive, closed-world write. The description adds genuinely new behavioral context: it needs MCP write actions and defaults to a non-applying preview unless confirm:true is passed, which tells the agent the first call mutates nothing. It stops short of saying what happens to an existing schedule when overwritten.

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?

Two tight sentences: the core operation and its scope come first, the write/preview constraint second. Every clause carries information; nothing is repeated from the schema verbatim.

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 7-parameter mutation with no output schema, the description covers the mutation semantics and the preview gate, which is the highest-risk part of calling it. Minor gaps remain: whether setting a schedule replaces an existing one and what the preview payload contains.

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%, so all seven parameters including confirm, previewToken, enabled and timezone are already documented in the schema. The description reinforces the confirm/preview contract and that the hour is in the client's timezone, but adds no syntax or format detail beyond the schema. 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?

Specific verb ('Set') plus a precisely scoped resource: when a client's keywords are checked, weekly, on a weekday/hour in the client's timezone, with an off switch. An agent can immediately tell this configures rank-tracking cadence rather than triggering a scan. It does not, however, distinguish itself from nearby siblings such as update_scan_settings or get_rank_tracking_setup.

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 description implicitly defines the use case (adjusting the weekly keyword-check cadence) and the confirm/preview flow, but never states when to prefer this over update_scan_settings or get_rank_tracking_setup, nor any prerequisites like required plan or permissions beyond 'requires MCP write actions'.

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