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

Annotations already establish write (readOnlyHint=false) and non-destructive behavior; the description reinforces this with the 'WRITE:' marker and adds genuine side-effect scope ('not added to any proposal'). It stops short of other useful behavior: whether a duplicate name collides, what the response contains, or how errors surface for a mutation.

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?

One front-loaded sentence with the operation class first, then the resource, then the disambiguating scope note. Nothing is redundant and nothing could be cut without losing signal.

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 7-parameter create endpoint with no output schema and 43% schema coverage, the description leaves the agent under-equipped: it does not say what is returned (e.g. whether the new fee's id comes back for later use in bidsketch_add_proposal_fee), nor explain the meaningful enum/quantity semantics. The type and scope are clear, but the call mechanics are not.

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 only 43% — name, amount, feetype, and category carry no schema descriptions at all. The description says nothing about any parameter: no guidance on the feetype enum values, what 'quantity' vs 'amount' mean together, or how 'custom' interacts with 'unit'. It neither compensates for the gap nor adds meaning beyond the schema.

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?

Specific verb+resource ('save a reusable fee on the account') with an explicit scope qualifier that separates it from the proposal-fee sibling: 'it is not added to any proposal.' An agent can distinguish this from bidsketch_add_proposal_fee or bidsketch_update_fee without inspecting the 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?

The parenthetical 'it is not added to any proposal' implicitly tells the agent when this tool is the wrong choice, which is real usage signal. However, it never names the correct alternative (bidsketch_add_proposal_fee) or states prerequisites such as whether a fee must be created here before it can be attached to a proposal.

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