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

Annotations already declare idempotentHint=true and destructiveHint=false, so safety is covered. The description adds genuinely new behavior: partial-update semantics ('only the provided fields are changed') and that the returned account carries a healthScore, pointing to get_sender_email for interpretation. Auth requirements and limit-conflict behavior remain unstated.

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 short sentences, front-loaded with the core action, then the partial-update rule, then sibling routing and return note. Every sentence earns its place with no redundancy.

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 an idempotent mutation with full schema coverage and no output schema, the description covers scope, partial-update behavior, sibling routing, and hints at the return payload via healthScore. Missing only edge details like validation failures or permission requirements.

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%, making 3 the baseline, and the description goes slightly beyond by grouping parameters into display name, signature, and daily-limit categories and clarifying the partial-update contract. It adds real meaning but does not explain the interaction between currentDailyLimit and the build-up limits.

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 (updates) and resource (a connected sending email account) plus the exact fields touched (display name, signature, daily sending limits). It also distinguishes itself from the similarly-named update_sender_email_warmup, so an agent can route without opening both schemas.

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?

Explicitly routes warm-up changes to update_sender_email_warmup and notes that only provided fields are modified, giving clear context for use. It stops short of naming the full when/when-not set (e.g., prerequisites like connected status or how it differs from connect_sender_email), so it is clear but not exhaustive.

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