Records a checked-out library book for a branch, with optional author; dates use YYYY-MM-DD, checked-out defaults to today, and due defaults to 21 days later.
Record a checked-out book. Dates use YYYY-MM-DD; checked_out defaults to today and due defaults to checked_out + loan_days (21).
| Name | Required | Description | Default |
|---|---|---|---|
| due | No | ||
| title | Yes | ||
| author | No | ||
| branch | Yes | ||
| loan_days | No | ||
| checked_out | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavioral disclosure. It helpfully states the date format and effective defaults for checked_out and due, but omits write side effects, validation/error behavior, and duplicate or availability handling.
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 compact sentences, front-loaded with the core action and then the date/default rules. No filler.
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?
An output schema covers return values, and the description gives the key date-default behavior for a loan-recording mutation. However, for a no-annotation write tool with required branch/title, it does not say enough about validation, failure modes, or how branch/title are resolved.
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 0%, so the description must explain the six parameters. It adds valuable meaning for checked_out, due, and loan_days (format and default derivation), but leaves required title and branch (and optional author) without any format or source guidance.
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 and resource ('Record a checked-out book'), so the agent can tell this creates a loan record rather than renewing or returning one. It does not explicitly name the sibling tools, so it falls short of full sibling differentiation.
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?
Usage is only implied by 'Record a checked-out book'; the agent can infer this is for new checkouts rather than renew_loan or return_loan. No explicit when-to-use/when-not guidance or named alternatives are provided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.