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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it is free, requires no account, returns ranked matches, and is a first-pass evaluation tool rather than a final answer tool. It doesn't describe pagination or exact return format, but the output schema exists and the annotations cover the safety profile, so a 4 is appropriate.

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 three sentences with zero waste. It front-loads the most important behavioral facts (FREE, no account), states the purpose, and then gives explicit usage guidance. Every sentence earns its place.

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?

Complete for a search tool with a rich output schema, full schema coverage, and annotations covering the safety profile. The description tells the agent when to use it, what it returns (ranked matches), and what it is not for. Nothing an agent needs to call it correctly 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?

Schema description coverage is 100%, so the schema already documents both parameters (query and limit) with descriptions, defaults, and constraints. The description adds the context that the query is a 'Bitcoin topic, concept, event, person, protocol feature, or research phrase' and that limit is the 'Maximum number of ranked knowledge matches to return', but this largely mirrors the schema. Baseline 3 is correct when the schema does the heavy lifting.

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 states a specific verb ('search'), a specific resource ('canonical Bitcoin Knowledge Atlas topics and related history'), and a clear purpose ('evaluate coverage on the caller's real question'). It also distinguishes itself from siblings by noting it is a no-cost evaluation tool for discovering maintained topic coverage, not a final evidence-grade answer tool.

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 explicitly says when to use it ('Run the first no-cost evaluation when you need to see which maintained Bitcoin topics and evidence match a query') and when not to use it ('Do not use when a canonical topic id is already known or when a final evidence-grade answer is required'). It also mentions the FREE/no-account aspect, which is a clear usage condition.

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