API health check

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

Annotations already establish that this is read-only and non-destructive, so the description does not need to repeat safety traits. It adds useful behavioral context: the tool probes external API reachability and helps disambiguate failure modes. It stops short of describing the exact return shape, but for a zero-parameter health check this is a minor gap.

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?

The description is two sentences with zero wasted words. The primary purpose is front-loaded in the first sentence, and the second sentence provides actionable usage context.

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 simple zero-parameter health check, the description is nearly complete: it states what the tool does, when to use it, and what diagnostic distinction it supports. It does not describe the return format, but given the tool's simplicity and the read-only annotations, this is acceptable and only mildly incomplete.

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 input schema is empty and schema description coverage is 100%, so there are no parameter semantics to document. The baseline of 4 applies because the description correctly implies the tool requires no inputs and focuses purely on a connectivity result.

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 uses a specific verb ('Check') and a specific resource ('the ESPN fantasy football HTTP API this server talks to'), and it clarifies the exact intention: verifying reachability. It is clearly distinguished from sibling data-retrieval tools like get_league or get_teams.

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?

It gives explicit usage guidance: 'Use this first when other tools fail, to tell "API is down" apart from "bad league config".' This tells the agent exactly when to invoke this tool and what diagnostic question it answers.

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