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

Annotations declare readOnlyHint=false and destructiveHint=true, which align with the description's mention of 'delete' as a destructive action. The description adds value by specifying the non-destructive actions (pause/resume, change amount) and the destructive one, providing clarity beyond the annotation flags. No contradictions.

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?

The description is a single concise sentence that front-loads the primary purpose and the three possible operations. Every word earns its place, with no redundant or filler content.

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 tool with 5 parameters and a destructive option, the description is too brief. It omits parameter interactions (e.g., whether 'delete' and 'paused' can be set together), the semantics of 'end_date', and the impact of changes on future payments. The output schema might clarify, but the description alone is insufficient for safe usage.

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 only 20% (only 'amount' has a description). The description maps actions to parameters: pause/resume to 'paused', change amount to 'amount', delete to 'delete', but it does not clarify the 'end_date' parameter or the required 'id'. It partially compensates for the low coverage but leaves gaps.

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 updates a recurring rule and explicitly lists three distinct actions: pause/resume, change amount, or delete. This specific verb+resource combination distinguishes it from add_recurring_rule and list_recurring_rules without ambiguity.

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 implies usage on existing rules through the verb 'update' and the sibling tool 'add_recurring_rule', but it does not explicitly state when to use it versus alternatives, nor does it provide exclusions or prerequisites. The guidance is implied rather than explicit.

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