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

Annotations already declare readOnly, non-destructive, closed-world, so the safety profile is covered. The description adds real semantic behavior beyond that: default newest-first ordering, the meaning of pageAccess versus reachedContent, and the rule that links must use checkUrl rather than raw screenshot/diff/HTML URLs. It stops short of describing pagination totals or result volume, keeping it below a 5.

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 purpose and field list are front-loaded, then alternatives, then result-interpretation and linking rules — a sensible information order with no filler. It is dense (four sentences plus clauses) but every sentence carries a distinct instruction, so nothing is clearly expendable.

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 ten parameters, no output schema, and a sibling that returns overlapping data, the description does the important work: it lists what a summary check contains, explains the evidence-link field, and routes detail-fetching to get_check. Remaining gaps (pagination behavior, what detail:true changes about the response shape) are minor and partly covered by the schema.

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 schema documents from/to, page, sort, limit, status, detail, taskPanel and includeHidden individually with defaults and bounds. The description's statements about newest-first ordering duplicate the sort default rather than adding syntax or format detail, 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?

Opens with a specific verb and resource ("List a monitor's past checks") and enumerates the returned fields (timestamps, status, alerted flag, percent difference, errors). It explicitly separates itself from get_check, which returns the full detail of a single check, so an agent can pick between the two 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?

Names the alternative tool and the condition that selects it: "Use get_check for the full detail of one check" and "To show one change to the user, open it once with get_check." It also gives outcome-level guidance (when reachedContent is false, report the challenge/login/error page rather than a content change), which is exactly the when-and-how an agent needs.

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