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

Annotations already declare the mutation profile (readOnly=false, destructive=true, idempotent=true), and the description adds genuinely useful non-structured behavior: partial-merge semantics ('Only the fields you pass are changed') and overwrite semantics ('each one replaces the stored value'), plus the cross-tool side effect on product search ranking. It doesn't state permission/auth requirements or what happens to existing arrays like health_goals, which keeps it from a 5.

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 tight sentences, with the usage trigger front-loaded before the behavioral details. The field enumeration in sentence one largely restates schema properties, so it isn't perfectly waste-free, but it doubles as a quick scan of scope.

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-optional-parameter mutation tool with no output schema, the description covers the trigger, the merge/replace semantics, and the cross-tool consequence, which is most of what an agent needs. Minor gaps remain around array-field replacement behavior and confirmation of the resulting state.

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% with enums and ranges documented inline, so the schema already carries parameter meaning. The description lists the field names but adds no format or syntax detail beyond what the schema provides; baseline 3 is appropriate.

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 states a specific verb (update/save) and resource (my profile) and enumerates the exact fields it accepts, so an agent knows precisely what this tool writes. It doesn't need to name a sibling because no other tool in the list updates profile data, though it also doesn't explicitly rule out overlap with suppco_save_memory.

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 trigger is explicit: 'Use this when the user gives profile details they want saved.' It also explains downstream context (saved preferences change defaults for other SuppCo tools). It stops short of saying when NOT to use it or pointing at a specific alternative, but the usage condition is clear.

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