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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive). The description adds valuable behavioral context beyond the annotations: it explains that etag is used as if_match on update and warns that content_rules is replaced as a whole, implying the need to fetch current settings before updating to avoid overwriting.

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 sentences, front-loaded with the return fields and followed by a critical usage note. Every phrase earns its place—no redundant or vague wording.

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 simple read tool with one parameter and no output schema, the description is complete: it enumerates the returned fields, explains the guardrails block, and provides the key pre-update usage rationale. Nothing essential is missing for an agent to call it correctly.

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% and the only parameter (account_id) is fully documented in the schema. The description adds no additional meaning, format, or source for account_id, so the baseline of 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?

States a specific verb ('Returns') and resource ('one account's persona, schedule_times, ...'), listing the exact fields and guardrails block. It clearly implies a single-account read, but does not explicitly name sibling alternatives like get_account_settings_batch or list_account_settings to distinguish when to use this vs those.

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 clear context: 'Applies before any settings change, because content_rules is replaced as a whole on update.' This tells the agent when to call it, but it doesn't list exclusions or alternative tools for related operations.

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