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

Annotations already cover read-only, idempotent, non-destructive behavior, so the description's added value is the freshness model: values are counted from chain as trades land and therefore represent a partial, moving day boundary in UTC, with yesterday shown alongside for comparison. It also states 'Free', which matters for cost-aware agents. It stops short of describing latency, caching, or how the yesterday comparison is presented, but it adds real context beyond the annotations.

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?

Front-loads 'Free' and the live/UTC framing, then the metric inventory, then the matching user questions, then the handoff to `stats`. Structurally sound, though the metric run-on is dense and one clause ('distinct traders and coins traded') could be trimmed without loss.

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?

With no parameters and no output schema, the description carries the burden of describing returns, and it does so by enumerating every metric plus the yesterday-comparison. Nothing essential to a correct zero-arg call is missing; only secondary details like ordering, refresh cadence, or units formatting are absent.

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 tool takes zero parameters, so the baseline is 4. The description correctly does not invent parameter semantics and instead spends its words on what the parameterless call returns, which is the right allocation.

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?

Names a specific resource and scope: pump.fun metrics for today so far in UTC, counted live from chain. It enumerates the exact fields returned (launches, graduations, migrations, trades, SOL/USD volume, distinct traders, large trades, dev sells, graduation rate) and explicitly distinguishes itself from the sibling `stats` tool, which covers a settled day.

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?

Gives concrete query intents ('how many coins launched today', 'volume today', 'how many graduated so far') plus an explicit exclusion routing to an alternative: 'For a whole settled day, use stats.' That is exactly the when-to-use / when-not-to-use / alternative structure an agent needs to choose between the two.

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