config_set

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

With no annotations, the description carries the full burden and does well: it discloses patch semantics ('Fields left empty are unchanged'), the file written and its 0600 mode, and a security constraint (secrets never pass through the model). It does not mention validation, error behavior, or that changes are immediate/persistent beyond the file write.

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?

Two short sentences, front-loaded with the action and target file, with the security caveat following. No filler; every clause earns its 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?

An output schema exists, so return values need not be explained, and the behavioral essentials are present. The gap is parameter meaning for an 11-field tool with zero schema descriptions, which keeps it from being fully 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?

11 parameters with 0% schema description coverage, and the description documents none of them individually (team_id, apple_id, asc_key_id, etc. are never explained). The only parameter-level meaning added is the general 'empty = unchanged' rule, which is insufficient to compensate for the coverage 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+resource: 'Write NON-secret settings to ~/.appfactory/config.toml (0600)'. It explicitly scopes itself against the secret-handling sibling by naming setup_credentials(), so an agent can distinguish it without opening the 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 a clear exclusion ('Secrets ... are refused here') and names the correct alternative (setup_credentials()), which is genuine when-not/when-to guidance. It does not, however, position itself against the other setup_* siblings, so routing among non-secret config tools is left to inference.

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