contacts_update

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

With no annotations, the description must explain behavioral traits. It only says 'Update a contact' without disclosing whether the update is partial or full replacement, whether omitted fields are preserved, or any permission requirements. Minimal behavioral disclosure.

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 short sentences, no filler. The key information (resource name source) is placed early and efficiently. Structure is ideal for a tool description.

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 it is a mutation tool with no annotations and a 0% schema description coverage, the description is too thin. It lacks update semantics (e.g., partial vs. full), which is critical for safe use. The output schema exists but does not compensate for the missing behavioral context.

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 0%, so the description must compensate. It only adds meaning for resource_name, explaining its provenance. The other six parameters (email, phone, etc.) rely solely on their titles and are not elaborated in the description.

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 clearly states the action: 'Update a contact.' The verb 'update' distinguishes it from sibling tools like contacts_create and contacts_delete. It also specifies the resource source, which makes the purpose unmistakable.

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?

It explicitly instructs that the resource name must come from contacts_search or contacts_list, giving clear context on how to obtain the required identifier. It does not mention exclusions or alternatives, but the usage context is clear enough.

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