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

The description adds real behavior beyond the annotations: it signals partial-success semantics ('Returns what saved, anything invalid, and what's still missing'), so the agent knows a call can half-succeed and must read the response. It does not state that previously stored values are overwritten, which is what the destructiveHint=true annotation really implies, so that key consequence stays implicit.

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 instruction is front-loaded and the long parenthetical list of field names is dense but necessary, since no enum exists in the schema. The enumeration is the bulk of the text, but every entry supplies a key name the agent otherwise could not guess.

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 a nested-object parameter, no output schema, and mutation annotations, the definition covers the valid input surface and the shape of the response. It omits prerequisites such as business_id provenance and overwrite behavior on repeat calls, which matters for a destructive, non-idempotent tool.

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 schema only describes 'fields' as 'Field name -> value' and leaves business_id entirely undocumented, so the description carries the load by enumerating every valid nested key with its expected format ('digits only', 'exact CAC picklist entry'). That closes most of the 50% coverage gap, though business_id's meaning and where to obtain it remain unexplained.

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 gives a specific verb plus resource ('Save registration form fields') and immediately bounds the scope with 'Only these fields can be set'. It distinguishes itself from read-side siblings such as get_registration_state and from helper siblings like search_line_of_business by being the only write path for form values.

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?

'from what the user told you' implies the trigger (collecting data during registration) and the hard constraint 'Only these fields can be set' prevents invented keys. However, it never names alternatives or next steps: it does not point to search_line_of_business for obtaining a valid CAC picklist entry, nor to get_registration_state for reviewing what remains, leaving the agent to infer the workflow.

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