Update Contact

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

With no annotations provided, the description carries the full burden of behavioral disclosure, but it only says 'Update a contact.' It does not reveal whether updates are partial/merge, whether authentication is required, what happens when conflicting identifiers are provided, or the response format. The schema descriptions add some parameter-level behavior (e.g., null to remove), but the overall operational behavior remains opaque.

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 a single sentence with no redundant words. It is front-loaded and easy to scan. However, it is extremely brief—almost under-specified—but the conciseness dimension rewards efficiency, and the sentence earns its place by stating the core action and identifier options.

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 mutation tool with 6 parameters, nested objects, no output schema, and no annotations, the one-sentence description is insufficient. It does not explain return values, partial update behavior, how 'properties' interact with existing data, or any side effects. The schema provides field-level detail, but the overall operation remains incomplete for an agent to select and invoke confidently.

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 baseline is 3. The description adds minimal value beyond the schema, only restating that updates happen by ID or email. Since the schema already documents each parameter's meaning (including null-to-remove semantics), the description does not need to compensate, but it also does not clarify the need for at least one identifier.

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 verb ('Update') and resource ('a contact'), and specifies identification methods ('by ID or email'). It distinguishes itself from sibling tools like create-contact or update-contact-property by focusing on updating an existing contact's fields.

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 provides no guidance on when to use this tool versus alternatives (e.g., update-contact-property, create-contact). It only states the action but does not mention exclusions, prerequisites, or preferred scenarios. The 'by ID or email' hint is more about identification than usage context.

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