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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds useful context beyond annotations by specifying the data source ('Computed from our own live recording of every pump.fun bonding-curve trade') and the 15-minute time window. It does not reveal potential latency or response format, but given the annotation coverage, this addition is sufficient for a 4.

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 (plus a price note) with zero filler. Key metrics and purpose are front-loaded, and every clause adds value: what it provides, how it is computed, and when to use it. The 'Price: free' note is brief and actionable. This is a model of conciseness.

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 tool with no parameters and no output schema, the description fully covers what an agent needs: the exact metrics returned, the time window, the data source, and a clear usage suggestion. Given the annotations already handle safety, nothing essential is missing. It is complete for its 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?

The input schema is an empty object with zero parameters, so schema coverage is trivially 100%. The description correctly does not attempt to explain parameters. Per the rule for 0-parameter tools, the baseline is 4. No additional semantic explanation is needed or possible.

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 states it is a live market heartbeat for pump.fun, listing specific metrics (trades/min, launches, graduations, graduation rate, hottest tokens in 15 min). This distinguishes it from siblings like pump_launches (list of launches) and pump_token (individual token data). The verb 'heartbeat' plus resource 'pump.fun market' is specific and unambiguous.

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 gives an explicit use case: 'Use it to decide whether the launch market is hot or dead before scanning individual tokens.' This tells the agent when to invoke it (before token-level analysis) and implicitly when not to (for individual token details). However, it does not explicitly name alternative tools or describe when to avoid it beyond that scenario, so it falls short of a 5.

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