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

With readOnlyHint=true already covering the safety profile, the description adds real behavioral context: the filters are applied client-side (so they don't reduce the fetch), and it enumerates the fields each check carries. It still omits pagination/result-size behavior, but the added detail is substantive.

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 sentences, zero filler, with the core list-and-what-it-returns statement front-loaded before the optional filtering detail and the endpoint reference.

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?

Because there is no output schema, the description usefully itemizes the return fields and clarifies filter semantics. It could add pagination or result-volume behavior, but for a simple read-only list tool the essentials are covered.

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 parameter meaning is already documented; notably the description adds the non-obvious fact that both filters operate client-side rather than server-side, which the schema does not convey. This is genuine value beyond the schema text.

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?

States a specific verb and resource ('List all monitoring checks on the account') and enumerates the returned data (status, uptime, last_status, error, period, SSL, domain expiry). This clearly separates it from the singular updown_get_check and the diagnostic updown_find_problems.

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 explains the optional status/search filters and their client-side nature, giving implied usage context, but never states when to prefer this over updown_get_check or updown_find_problems, nor any exclusion or prerequisite.

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