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

With no annotations, the description carries the full burden, and it does disclose two useful traits: the tool is a read operation and results are bounded to the last 24 hours. It also flags the data as synthetic/measured rather than true uptime. However, it says nothing about the enum scenario values malformed and unavailable, which strongly imply the tool can deliberately return error or empty results — a behavioral trait an agent must know before calling.

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 short sentences, front-loaded with the core action and time window, with no filler. The trailing negation is compact, though it is the least self-explanatory clause and could have been phrased as a positive statement of what the data represents.

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 one-optional-parameter read tool with no output schema, the description covers time scope, data provenance, and one important limitation. Under-specified: the distinction from live_history and the effect of the scenario parameter on return behavior, but neither is fatal for a small tool.

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?

The single scenario parameter is fully documented by its own enum values (healthy, malformed, unavailable), so the schema leaves no ambiguity for the agent.

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?

"Read measured synthetic check history over the last 24 hours" gives a verb and a resource but leaves the key distinction unresolved: the tool is named demo_history and sits beside live_history and check_live, yet nothing explains what "demo" means or how this differs from the live variant. The negating sentence "NOT independent uptime monitoring" rules out one misreading without affirmatively stating what the data is.

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?

There is no when-to-use guidance and no alternative is named. "NOT independent uptime monitoring" is a scope disclaimer, not an instruction telling an agent when to pick this over live_history or check_demo. The agent must infer selection from sibling names alone.

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