mailer_config_update

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

No annotations are provided, so the description carries the burden. It correctly identifies the tool as a mutation (create/update), states the plan restriction, and discloses the password-preservation behavior on update. Doesn't mention SMTP connectivity failures or validation behavior, but covers the key behavioral contract.

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 tight sentences with zero waste. Front-loads the core purpose, adds the important plan restriction immediately, then discloses the critical password-omission behavior. 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?

For a config mutation with 8 well-documented parameters (100% schema coverage), the description adequately covers purpose, plan gating, and the key update nuance. No output schema means return value isn't described, but for a write operation this is a minor gap.

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 detailed per-parameter descriptions, so the schema does the heavy lifting. The description adds the password-omission update nuance and the 'fromAddress must be authorized' context is already in the schema. Baseline 3 is appropriate.

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?

Clear verb+resource: 'Create or update the organization's custom email sender'. Explicitly states it's Business plan only and that invoices/receipts/delivery notes go through this SMTP server. Distinguishes from sibling mailer_config_get/delete/test by declaring it's the create/update counterpart.

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?

States the Business plan constraint and that this config affects email sender behavior for business documents. Notes the password-omission convention for updates. Doesn't explicitly contrast with mailer_config_get/delete/test, but the plan restriction and idempotent create/update nature give useful context.

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