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

Annotations only supply readOnlyHint=true, so the description usefully adds what actually comes back (per-period start/end timestamps and duration in ms) — valuable since there is no output schema. It omits pagination behavior, though the schema's 'before'/links.next note partially covers that.

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?

Three short, front-loaded sentences: what it returns, the intent it answers, and the backing API endpoint. Every sentence earns its place with no filler.

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 read-only, single-resource query tool with full schema coverage, the description supplies the return shape it would otherwise lack. Only paging guidance is absent, and that is already implied by the 'before' parameter description.

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% — after, before, limit and test_id are all documented with types, ranges and defaults in the schema. The description adds no parameter-level information, 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?

States a specific verb+resource ('the up and down periods of one uptime check') and names the returned facts — start, end, duration in ms — which distinguishes it from siblings like statuscake_get_uptime_history or statuscake_list_uptime_alerts without opening a 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?

The line 'the direct answer to how long was it down?' gives a clear intent-based routing cue for when this tool is the right pick. It stops short of naming an explicit alternative (e.g. uptime_history for aggregate percentages) or a when-not-to-use condition, so it does not reach 5.

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