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

The description accurately states read-only behavior, matching the readOnlyHint annotation, and adds that only the owner can edit via settings. This provides additional behavioral context beyond annotations.

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 concise sentences front-load the action and include key constraints. No unnecessary words or irrelevant details.

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?

The description covers the basic action and read-only nature but lacks details on return values or what 'spend safety limits' entails. Given no output schema, this omission reduces completeness for a tool with one parameter.

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?

The single parameter 'meta_account_id' has no description in the schema (0% coverage), and the description does not explain its purpose or format beyond referencing 'an account'. This leaves meaning unclear for the agent.

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?

The description clearly states the tool views spend safety limits for an account, using a specific verb and resource. Among siblings focused on campaigns and ads, this tool's purpose is distinct and unambiguous.

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?

The description mentions it is read-only and editable only by the owner in settings, implying when not to use for editing, but does not explicitly state when to use this tool versus alternatives or provide usage context.

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