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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds meaningful context beyond that: the operation is free, the feed_lag_s metric has a precise definition, and the tool contains no per-mint data. This is sufficient for a zero-parameter health check.

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 compact sentences carry all the essential information: cost, metric definitions, purpose, and a limitation. Everything earns its place and the most important usage guidance comes last without padding.

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 zero-parameter read-only health tool with no output schema, the description is complete. It tells the agent what metrics to expect, how to interpret feed_lag_s, when to call the tool, and that it lacks per-mint data. Nothing critical is missing.

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 are zero parameters and the schema is empty, so the baseline is 4. The description doesn't need to explain parameters; it instead clarifies what the response will contain, which is more relevant for this tool.

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 clearly defines the resource ('feed health') and enumerates the exact metrics returned: feed_lag_s, is_stale, last Solana slot, mints tracked, and counters. It lacks an explicit verb like 'get' or 'fetch', and it doesn't name a sibling tool, but the scope is obvious enough to distinguish it from per-mint and analytics siblings.

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 guidance: use it before trusting a card's freshness. It also states what it is not for ('carries no per-mint data'), which tells the agent when not to rely on it. It doesn't name specific alternative tools, but the context is clear and actionable.

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