Update contact

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

No annotations, so the description carries the full burden. It does disclose one genuinely useful behavior — multi-valued fields keep their other entries, i.e. partial/additive semantics — but never says what happens to fields not supplied (cleared vs. preserved), whether the operation is reversible, or what auth/permissions are needed.

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, no waste, with the mutable-field scope front-loaded before the behavioral caveat. Every clause 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 an 8-parameter mutation tool with no annotations and no output schema, the description covers which fields can change but omits the key open questions: partial vs. full replacement for omitted fields, failure behavior for an invalid resourceName, and confirmation of what is returned.

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 88%, so the schema already documents name, email, phone, account, address, photoBytes, organization, and resourceName. The description only echoes the field list and adds the multi-valued retention nuance, which is marginal value on top of an already well-documented 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?

States a specific verb ('Update') and resource ('a contact's') and enumerates the mutable fields, so the agent can tell it apart from google_contacts_create, google_contacts_get, and google_contacts_delete. It does not explicitly name those siblings, but the operation is unambiguous.

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 on when to use this versus google_contacts_create or google_contacts_search, and no mention that resourceName must come from a prior list/search call (that hint lives only in the schema). Usage is only implied by the word 'update'.

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