core_set

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

Discloses sorting by priority DESC, content cap 1KB, and priority range beyond annotations. Annotations already indicate idempotency and non-destructiveness, so description adds value without contradiction.

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?

Four sentences, each essential: purpose, usage guidance with sorting, examples, parameter details. Front-loaded with most critical info. No fluff.

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?

Covers purpose, usage, parameters, and behavioral traits. Output schema exists, so return value explanation is not needed. Could mention idempotency explicitly, but annotations cover it. Nearly complete.

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?

With 0% schema description coverage, the description fully compensates by explaining key (implied identifier), content (1KB cap), and priority (0-100, default 50, higher shown first). Adds significant meaning beyond raw schema.

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?

Clearly states 'Upsert a core-memory entry' with a specific verb and resource. Distinguishes from siblings like core_get, core_list, core_remove by mentioning the ALWAYS shown sorting behavior. Provides examples of good vs bad usage, reinforcing purpose.

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?

Explicitly advises to 'use sparingly' and defines the tool as the 'what new-claude must know' surface, not a note store. Gives concrete good/bad examples. Does not explicitly name alternative tools for note storage, but strongly implies usage constraint.

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