Remember a preference

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

No annotations are provided, so the description carries the full burden. It discloses that it modifies AGENTS.md, explains scope behavior, and states it is about agent behavior/preferences. It does not mention destructive side effects or permissions, but it is largely transparent.

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 a single paragraph that is well-structured and front-loaded with the main action. Every sentence earns its place, though it could be slightly more concise.

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?

Given the tool's complexity (3 parameters, no output schema), the description covers when to use, what to do, scope, and sibling differentiation. It provides sufficient context for correct invocation, though details like date format are omitted (minor).

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 baseline is 3. The description adds value by explaining phrasing requirements ('durable rule, ideally with a short WHY'), scope distinction, and when the project parameter is required. This goes beyond the schema's property descriptions.

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 clearly states the tool appends a dated bullet under '## Preferences' in AGENTS.md, turning user corrections into remembered patterns. It explicitly distinguishes from siblings like append_decision and log_issue.

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 description provides explicit guidance: call proactively when the user corrects how you work or states a durable preference, and tell the user what was saved. It also contrasts with siblings: 'for a project DECISION use append_decision, for a bug use log_issue'.

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