Save a durable memory

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

Annotations indicate mutation (readOnlyHint=false) and non-destructive behavior (destructiveHint=false). Description adds valuable behavioral details: near-duplicates are merged automatically, obvious secrets are refused, and it returns the saved memory id. This goes beyond what annotations provide.

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?

Description is three sentences, each serving a distinct purpose: stating the function, giving usage guidelines, and disclosing behavioral traits. It is front-loaded with the core purpose, and every sentence earns its place without redundancy.

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 no output schema, the description covers the return value (saved memory id). It adequately addresses when to use, parameter hints, and behavioral traits. May lack details on error handling, but overall complete for a tool of this complexity.

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% with descriptions for all 5 parameters. The description adds practical usage tips: project should be git repo name, content should be a single atomic idea, source should be left as default, confidence is optional. This adds value beyond the schema alone.

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?

Description clearly states the tool persists a durable memory fact, enumerating specific fact types (decision, lesson, fix, convention, status) and specifying it's for future sessions. It distinguishes from siblings like ygg_recall and ygg_search, which are retrieval tools, by emphasizing write behavior.

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?

Description explicitly advises when to call the tool ('right after you decide something, learn a lesson, or fix a non-obvious bug') and provides a guideline to store one idea per call. It does not mention alternatives or when not to use it, but the context is clear enough.

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