mind_block

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

With no annotations, the description carries the burden and does well: it discloses the injection behavior, per-action semantics (set overwrites, get/list read, remove deletes), and hard resource limits (4KB/block, 32 blocks). It does not state what happens on overwrite of a missing block or whether remove is recoverable, which is the remaining gap for a mutation tool.

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-loads what the tool is and the ALWAYS-injected constraint, then actions, then limits, then the sibling alternative. Dense but every clause adds an operational fact; only the parenthetical example list is mildly expendable.

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 3-param mutation tool with no annotations and no output schema, the description covers purpose, action semantics, capacity limits, and alternatives. Only edge-case behavior (overwrite of a nonexistent block, reversibility of remove) remains undocumented.

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 a documented enum, so the baseline is 3, but the description adds semantics the schema lacks — that 'set' overwrites existing content and that 'list' needs no name — plus the storage cap that bounds what content may be passed.

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?

Names the specific resource (pinned core-memory blocks: persona/user/current-project) and its defining behavior (ALWAYS injected at top of session context, not ranked retrieval). This distinguishes it clearly from retrieval siblings like mind_search and mind_recall.

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?

Explicit when-to-use ('stable, always-relevant facts the agent must not have to search for') paired with an explicit when-not and named alternative ('put searchable knowledge in mind_add instead'). No inference required to route between the two tools.

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