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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context the annotations cannot convey: the tool is metered ('PAID 0.15 USD via MPP'), which materially affects invocation decisions. It does not cover auth requirements, latency, or failure modes.

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 price disclosure is front-loaded, which is good. However, the evidence categories are enumerated twice in near-identical phrasing, and the final sentence largely restates the second ('supporting, conflicting, and contextual evidence around a focused target'). Some redundancy that could be trimmed.

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?

An output schema exists, so return-value detail is not required, and annotations cover the safety profile. The description supplies the missing pieces an agent needs: cost, input intent, and positioning against answer-style siblings. Auth and pagination/limits for a paid multi-source fetch are the only notable gaps.

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, so the schema already fully documents 'query'. The description adds framing about the research question being 'focused' and single-target, but no syntax, format, or constraint details beyond what the schema provides. Baseline 3 is 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?

States a specific verb+resource ('Build a focused Bitcoin evidence package') and enumerates exactly what the package contains: compact source material, atomic claims, conflicts, source authority, exact-locator precision, caveats, provenance, temporal scope. It explicitly distinguishes itself from answer_bitcoin_question and answer_bitcoin_question_with_evidence by saying it does not compose the final answer or a narrative dossier.

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 a clear selection condition ('when the agent already knows what it is researching and primarily needs compact source material') and an exclusion ('rather than a verdict or narrative dossier'). It stops short of naming the specific sibling tools (answer_bitcoin_question_with_evidence, verify_bitcoin_claim) that an agent would otherwise weigh, so routing is inferred rather than explicit.

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