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

Annotations already declare destructiveHint=true and readOnlyHint=false; the description adds the crucial PATCH semantics ('only the fields you pass are sent') and the underlying PUT endpoint, which tells an agent how to structure a safe partial update. It doesn't mention totals recalculation or other side effects, but the safety-relevant behavior is disclosed.

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 front-loaded sentence leads with 'WRITE:', then the effect, then the partial-update rule, then the endpoint. No wasted text.

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 mutation the description covers input shape semantics and the endpoint, but omits what happens to proposal totals when a fee price changes and whether the change is reversible – relevant for a tool annotated destructiveHint=true.

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 80%, so most parameters (amount, feetype, quantity, optional) are documented at the field level. The description adds no parameter-specific guidance, which is acceptable at this coverage level, but doesn't earn extra credit.

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 ('change') and resource ('a fee line of a proposal'), immediately distinguishing it from read siblings and from the library-level update_fee. It doesn't name the sibling it supersedes, but the phrase 'fee line of a proposal' is precise enough to disambiguate.

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 'WRITE:' prefix and the 'only the fields you pass are sent' clause give clear context that this is a partial-update mutation on an existing fee line. It doesn't explicitly contrast with bidsketch_add_proposal_fee or bidsketch_update_fee, but the context is unambiguous.

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