library_shelve

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

Annotations already convey read/write and non-destructive naturechers (readOnlyHint=false, destructiveHint=false). The description adds the 'durable' framing but does not disclose potential side effects like overwriting an existing book_id or limitations on size. It does not contradict annotations, but also goes beyond them minimally.

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 description is two sentences, front-loads the purpose, and is free of fluff. Every sentence contributes to understanding the tool's role and scope.

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 write-oriented tool with no output schema and several optional parameters, the description gives enough to understand the top-level function but leaves parameter semantics to the schema. It is a minimum-viable description, but given the tool's complexity and low schema coverage, it falls short of fully informing usage.

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 low (29%), and this description adds no parameter-specific meaning. It only hints at content type ('concise book') but does not explain text, source, book_id, importance, or shelf_life_seconds. Since coverage is low, the description should compensate, but it does not.

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-resource pair ('Persist ... to the local Library') and clearly defines the domain (durable context, not chatter). It distinguishes itself from siblings like library_desk_stop and library_consult by focusing on persisting a book of context.

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?

Provides explicit positive guidance ('Use for durable decisions, constraints, findings, and user-approved memories') and negative guidance ('not transient chatter or secrets'), which helps an agent decide when to invoke it. However, it does not mention alternatives or exclusions relative to sibling tools (e.g., library_shelve_document).

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