pin

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

Annotations cover safety (readOnlyHint=false, idempotentHint=true, destructiveHint=false), but the description adds behavior annotations cannot express: replica writes queue instead of failing, refusals are loud for binding-incapable kinds, and pinned items are exempt from mark's verdict. Return values are also 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?

Front-loaded with the core action and effect scope, then conditions and return values. Every sentence carries a distinct fact, though the clause density with dashes and parentheticals is heavier than a one-parameter tool strictly needs.

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?

No output schema exists, yet the description enumerates the three possible responses ('pinned' with event sequence, 'already pinned', or refusal text) and covers the replica/queue and kind-refusal edge cases. An agent has everything needed to call and interpret this correctly.

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 the baseline is 3, but the description adds real constraint semantics beyond 'The id to pin': the id must reference an existing item, and ids whose kind cannot bear a binding are refused. That is meaningful eligibility information the schema does not carry.

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 concrete verb+resource: 'adds the Always binding to an existing item', and immediately scopes the effect ('every other binding and field stays untouched'). It differentiates from siblings by naming mark (which refuses pinned items), unpin (the inverse), and revise (the alternative for non-binding changes).

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?

Gives explicit when-to-use and when-not-to-use: 'Use revise instead when anything besides the binding needs to change', plus the exact refusal condition (kinds that may carry no binding, e.g. Report or Chunk). It also routes the agent to unpin as the undo path.

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