backfill_history

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

Discloses async nature, caching, request anchoring, that WhatsApp controls how far back it serves, and return fields (cacheBefore/cacheAfter). No annotations provided, so description fully handles transparency.

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?

Concise paragraph with clear flow: purpose, mechanism, limitation, return info. Every sentence adds value.

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?

Given no output schema, description explains return values and what to do if results are poor. Covers async behavior, caching, and fallback sufficiently for an agent.

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 covers 100% of parameter descriptions, so baseline 3. Description does not add new parameter-level detail beyond context but reinforces usage context.

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?

Clearly states the tool recovers missed WhatsApp messages when the bridge was offline, with specific verb 'recover' and resource 'history'. Distinguishes from siblings like relink_whatsapp by positioning it as a fallback.

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?

Explicitly says when to use ('bridge was offline') and when not to expect full history (WhatsApp decides). Provides alternative (relink_whatsapp) if messagesAdded is ~0.

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