Update function

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond them: unspecified fields are preserved (patch semantics). It says nothing about permissions, failure modes, or what happens if the function uid/name does not resolve.

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?

A single sentence with no filler, and the core behavior is front-loaded before the partial-update caveat. Nothing could be cut without losing information.

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?

Adequate for a two-parameter mutation with full schema coverage and no output schema, but the `changes` object is `additionalProperties: {}` with no enumeration of valid field names in either the schema or the description. An agent still does not know what can actually be changed.

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 both parameters ('function': uid or exact name, 'changes': fields to change) are already documented, making 3 the baseline. The description's 'fields not given keep their values' clarifies patch semantics for `changes`, but it never enumerates which field names are legal inside that free-form 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?

States a specific verb and resource ('Change fields of an existing function'), and 'existing' implicitly separates it from create_function and delete_function in the sibling list. It is clear without needing to open the schema, though it never names a sibling explicitly.

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?

There is no explicit when-to-use guidance, no prerequisites (e.g. that the function must already exist), and no routing to alternatives such as create_function or delete_function. Usage is only implied by the word 'existing'.

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