Manage Inbox Rule

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

Annotations declare it is not read-only, not idempotent, open-world, and not destructive; the description adds real behavioral context by disclosing that destructive-effect rules act silently on future mail and therefore require confirm=true, plus that the rule is returned. It doesn't spell out the consequence of confirm=false (rejection vs. silent drop) or auth/permission requirements, so it stops short of a 5.

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 sentences, zero filler. The capability statement comes first, the safety gate second, and sibling routing last — well front-loaded and each sentence 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 8-parameter nested mutation tool with an output schema already documenting return values, the description covers all four action modes, the confirm safety requirement, and delegation to sibling tools for read/delete. Nothing needed to call it correctly is missing.

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 description coverage is 100%, so parameter docs already exist; the description still adds rationale the schema lacks, explaining why confirm is required (silent future-mail action) and that the call returns the rule. It does not, however, clarify action/parameter pairings (e.g., rule_id required for set_enabled/reorder), which the schema only partially implies.

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 and resource and enumerates the four concrete modes (create, change, enable/disable, reorder), so the agent knows exactly which operations this tool covers. It also implicitly separates itself from read/delete siblings by naming them in the next sentence.

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?

Explicit routing is given: read rules with m365_list or m365_get, delete with m365_delete. It also states a conditional gate ('Rules that forward, redirect or delete mail require confirm=true'), which is exactly the when/when-not guidance an agent needs before invoking.

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