update_contact

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

Annotations already provide idempotentHint=true, readOnlyHint=false, destructiveHint=false. The description adds no additional behavioral context, such as whether the update is a full replace or partial merge, what happens to unspecified fields, or if there are any 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?

The description is a single sentence that is concise and covers the main purpose. No unnecessary words. Could be slightly expanded without becoming verbose.

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 the tool has 5 parameters including a nested object and no output schema, the description is incomplete. It lacks information about return values, error handling, or the nature of the update (partial vs full). Idempotency hint is not leveraged in the description.

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?

The description adds meaning beyond the schema for 20% coverage by mapping first_name/last_name to 'name', unsubscribed to 'subscription state', and properties to 'custom properties'. However, it does not explain the format or constraints of these parameters, especially the custom properties object.

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 the resource 'contact'. It lists specific updatable aspects: name, subscription state, or custom properties. This distinguishes it from create, delete, get, and other contact tools among siblings.

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?

No guidance is provided on when to use this tool versus alternatives (e.g., update_contact_property, create_contact). There is no mention of prerequisites, such as the contact must exist, or scenarios where it should not be used.

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