update_friend_memory

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

With no annotations, the description carries the full burden and does so well: it discloses the destructive replace semantics, the merge alternative, persistence across sessions, and a 4 KiB JSON size cap. No behavioral surprises are hidden.

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?

Three sentences with no filler. The most safety-critical fact (full replacement) is front-loaded, and the example and size cap earn their place.

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 two-parameter write tool with an output schema, the description covers semantics, merge behavior, persistence, and limits. Nothing required for a correct call is missing, and the sibling routing is implied through the get_friend mention.

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 0%, so the description must compensate. It does for `memory` by giving a concrete example and explaining the JSON-encoded blob semantics; `friend_bot_id` is left to its self-explanatory name and 'per-friend' qualifier, a minor gap.

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 specific verb ('Write') and resource ('persistent per-friend memory blob'), and immediately distinguishes itself from get_friend by warning that it replaces rather than merges. This makes its function unambiguous.

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?

Provides explicit merge workflow: call get_friend first, pass merged dict. Also tells the agent when to use it ('stash facts learned across cold-started sessions'), so the tool's invocation context is clear.

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