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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description adds which fields come back, which is useful context, but says nothing about pagination behaviour or that nouptime trades uptime accuracy for speed on large accounts — both of which the schema only gestures at.

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 with no padding: what it lists, what can be filtered, and the underlying endpoint. The trailing 'StatusCake: GET /uptime' is marginally useful API context rather than 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 list tool with no output schema, the description usefully enumerates the returned fields and the two filter dimensions, and annotations cover the safety profile. Remaining gaps (pagination semantics, when to prefer a sibling tool) are minor.

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%, so every one of the six parameters is already documented in the schema; baseline 3 applies. The description restates the status and tags filters but adds no syntax or interaction detail (e.g. tags+matchany interplay) beyond the schema.

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?

Specific verb+resource ('List uptime checks') plus an enumeration of the fields returned (status, type, URL, check rate, tags, uptime percentage), which lets an agent distinguish it from statuscake_list_ssl_checks / list_heartbeat_checks / list_pagespeed_checks. It does not explicitly contrast with get_uptime_check or list_uptime_alerts, so no sibling routing is spelled out.

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 says 'Filter by status or tags,' implying the supported use, but gives no when-to-use/when-not guidance and names no alternative tool (e.g. get_uptime_check for a single check, list_uptime_alerts for alerts). Usage is inferable but not stated.

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