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

The description explicitly discloses partial-update behavior: 'Only provided fields are updated; omitted fields are left unchanged.' This adds practical value beyond the annotations, which already indicate the operation is non-destructive and idempotent. It gives the agent confidence about repeated calls and field-level side effects.

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?

Two sentences with no filler: the action and target are front-loaded, the caller context is stated, and the important behavioral caveat is included. 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?

For a simple mutation with annotations and an input schema, the description covers the action, the fields involved, the partial-update behavior, and the intended invocation context. It doesn't describe response behavior or error cases, but no output schema is provided and those details are not essential for correct invocation.

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 only 20% (only workspaceId is described), so the description must compensate. It does clarify that email, phone, and website are the contact fields being saved, and the partial-update rule explains how omitted optional fields behave. leadId is implied as the target but not explicitly described; still, the description covers the most important semantic gaps.

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 ('Save'), resource ('contact information'), and target ('to a lead'), making the core purpose clear. It is more specific than the generic 'update lead' wording, but it does not explicitly contrast with sibling tools like campaignstack_update_lead_metadata or campaignstack_enrich_lead_contact_info, so it misses the full 5.

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 a clear invocation context: it is called by the linkedin-contact-info agent after extracting data from LinkedIn's Contact Info overlay. This tells an agent when this tool is appropriate, though it doesn't name alternatives or state when not to use it.

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