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

States that only passed fields are changed ('omit the rest'), consistent with idempotentHint=true. No contradiction with annotations. However, does not disclose any authorization requirements or return behavior.

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?

Three sentences with no wasted words. Front-loaded with verb and resource, then lists updatable fields, then usage guidance and key behaviors.

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?

Adequate given low complexity—no output schema, but the operation is straightforward. Could mention the return value (e.g., updated contact object) but not required.

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 coverage is 100% and each parameter has a clear description. The description adds value by explaining that only provided fields are updated, which is not explicit in the schema.

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?

Description explicitly states 'Update a lead's contact details' and lists the specific fields (email, phone, location, company, position, headline). This clearly differentiates from sibling tools like 'set_lead_fields' or 'enrich_contacts'.

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?

Provides explicit use case: 'Use to enrich a lead (e.g. save an email address you found).' Also clarifies that it does not create contacts, but does not mention when to use alternatives like 'create_contact'.

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