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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the write/safety profile is covered. The description adds real value on top: it discloses the 1-300 character constraint and, importantly, what the result reports back — whether the feedback was saved and which scope it landed in (a style cohort or person-wide rules). That outcome/scoping disclosure is the useful behavioral detail; it does not cover failure modes or idempotency (left to the schema).

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 trigger condition is front-loaded after the purpose statement, which is good. But the closing sentence 'Save one writing preference for the person (1 to 300 characters)' repeats the opening verb and the length constraint already stated two sentences earlier, so three of four sentences carry unique information and the fourth is dead weight.

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 a six-parameter write tool with full schema coverage, rich parameter descriptions, an output schema, and annotations, the description supplies what structured fields do not: the trigger condition and the meaning of the returned scope. Nothing an agent needs in order to decide to call it or to interpret the outcome is missing, though a note on when not to use it versus sibling preference tools would round it out.

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 the baseline is 3. The description restates the feedback length bound already in the schema and alludes to the cohort/person-wide distinction that maps to cohort_id, but it says nothing about workspace_id, conversation_id, workspace_scope, or idempotency — all of which the schema documents thoroughly on its own.

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 opens with a specific verb and resource: 'Record a writing preference for the caller.' Combined with the trigger phrase 'feedback about their own writing style', an agent can tell this apart from the broader preference tools (well_upsert_preference) and from well_create_writing_style_training. It stops short of explicitly naming those siblings as alternatives, which keeps it from a 5.

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?

'Use it when the caller gives feedback about their own writing style' is a clear, concrete trigger condition. However, it gives no exclusions or boundaries against adjacent tools such as well_upsert_preference or well_create_writing_style_training, so the agent must infer those distinctions itself.

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