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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds crucial behavioral specifics: it reads recorded events, only exists while alerts are enabled, and provider-limited engines generate nothing to avoid false alarms. This substantially enriches the annotation-only profile.

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 description is three sentences, with the core purpose front-loaded and caveats following. It is informative without being verbose, and every sentence adds value—defining event types, clarifying read-only nature, and explaining conditions for event existence.

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 list tool with pagination and no output schema, the description covers the key context: what events are, when they exist, and how to interpret absence. It references the settings tool for enabling alerts. It doesn't describe the return format, but the absence of an output schema and the straightforward nature of the tool make this 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?

Schema description coverage is 100%, so all parameters (site_id, limit, offset) are documented in the schema. The description does not add any parameter-specific semantics beyond what the schema already provides, aligning with the baseline of 3 for full coverage.

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 action ('list recent rank-change alert events') and resource ('for one RankParse website'), and defines what counts as a significant move (entered/left top 3/10, threshold crossings, new/lost). It clearly distinguishes this from other ranking tools by focusing on alert events rather than raw rankings or live checks.

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 explicitly says 'never runs a live check' and explains that absence of events means no significant moves, which guides when to use it. It also references get_rank_alert_settings for enabling alerts, providing context, though it doesn't explicitly name alternatives like get_keyword_rank_history. This is clear enough for routing.

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