Keychain secret

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

Adds substantial behavior beyond the annotations: no copy is kept, no sync or team space can reach the store, an env var of the same name wins, a missing secret returns found:false rather than an error, and values are never printed back unless the user asked. These are non-obvious operational traits the agent must know.

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-loaded with the core purpose and dense with useful constraints per sentence, though it is a single long paragraph covering five actions. Efficient, but slightly run-on where per-action structure would scan faster.

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?

No output schema exists, so the description carries return-value burden — and it does, describing get's value/found:false semantics, list returning names only, and status reporting which store exists or that none is normal. Nothing needed to invoke it correctly is missing.

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 description coverage is 100%, so the schema already documents name, value, action, and description fully. The description restates the SCREAMING_SNAKE_CASE convention and adds that set rejects empty values, but adds little else beyond the schema baseline.

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+resource — read or write credentials in the OS keychain — and immediately distinguishes itself from siblings by naming crbro_learn as the place to record only the NAME. An agent can tell what this tool stores versus what the memory tools store without opening any schema.

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?

Gives concrete when-to-use guidance ('when the user hands you a credential, set it here, then record only the NAME with crbro_learn') and routes the read path explicitly, including the env-var-wins precedence rule. The alternative tool is named and the condition selecting each path is stated.

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