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

Annotations already declare destructiveHint=true, but the description explains precisely what is destroyed and how: omitted entries in a sent section are dropped, so every retained entry must be re-sent with its id. It also discloses the validation rule (unknown section names refused) and a response token cost, all beyond the annotations.

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?

Three labeled fragments (Purpose/When/Cost) front-load the replacement rule first, then usage, then cost. Every clause carries non-redundant operational information; nothing is padding.

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 destructive, nested-object mutation the description covers replacement semantics, id requirements, validation limits and cost. With an output schema present it correctly does not waste words describing the returned profile shape.

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 100%, so baseline would be 3, but the description adds decisive semantics the schema does not state: whole-section replacement, id reuse from a prior read, and the ten-section limit. These change how an agent constructs the payload, not merely what it names.

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 and target ('Replace whole sections of the user's profile') and immediately clarifies the replacement semantics — a sent section overwrites the stored one in full. That distinguishes it from any partial-patch sibling and from profile_get without needing to open a schema.

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?

Explicit activation condition ('the user asks to add, fix or remove something in their profile') with an exclusion ('not on the assistant's own initiative'). It stops short of naming profile_get as the mandatory read-it-first companion, only alluding to 'the ids read earlier'.

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