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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety and repeatability profile is fully covered. The description adds only the notion of a responsiveness check and does not disclose that the response echoes the supplied message or what a failure looks like, which would have been genuinely additive.

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?

One short sentence with the key information front-loaded and no redundancy. The lead-in 'A basic tool to' is mild filler that could be trimmed, keeping it just short of a 5.

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 single-parameter, non-destructive health check with full annotation coverage and no output schema, the description gives enough to call it correctly. The only real omission is what the tool returns (presumably an echo of the message), which is a minor gap given the simplicity.

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 ('A custom message to send back'), so the schema carries the semantics. The description does not mention the message argument or its echo behavior at all, so it adds nothing beyond the schema, making the baseline 3 correct.

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?

The description names a specific action (check) and target (whether the Supabird MCP is responding), which is unmistakably a health/connectivity probe and cannot be confused with any of the functional siblings listed. The word 'basic' adds nothing, but the core purpose is stated cleanly.

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?

Usage is only implied: an agent can infer this is a diagnostic to run when connectivity or server health is in question. There is no explicit guidance such as 'use when another tool returns an error' or any statement that it is not a substitute for functional calls, and no alternatives are named.

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