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

Annotations already declare a safe read-only, closed-world operation, yet the description still adds real behavioral insight: what pageAccess means, and that reachedContent=false signals a challenge/login/error page that should be reported as such rather than as a content change. That interpretive rule is the kind of context annotations cannot convey; only the absence of pagination/error behavior keeps it from 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?

Front-loaded with purpose, then interpretation rules, then usage exclusions and linking conventions. Every sentence is functional, but the paragraph is dense and mixes several distinct concerns (return values, pageAccess semantics, sibling avoidance, link format) without separation, which costs a little scannability.

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 no output schema and a single trivial input, the description carries the full burden of explaining return values and does so thoroughly, down to naming the artifact types. An agent has enough to call it and to interpret and report the result correctly.

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?

There is a single parameter with 100% schema description coverage ('Monitor uuid (from list_monitors)'), so the schema already carries the semantics. The description adds no further detail about the uuid format or where else it can be sourced, so the baseline of 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 ('Get a monitor's most recent completed check') and then enumerates exactly what comes back: status, alert flag, extracted output, AI summary, artifact URLs. It is clearly distinguishable from siblings like get_check and get_check_history.

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?

Explicitly states when to use it ('what is the price now?', 'did anything change?') and adds a hard exclusion: 'do not also call get_check for the same check' because the card is already shown. It also prescribes linking behavior with checkUrl, guiding downstream use.

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