Set scenario sender permissions

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

Annotations already mark the operation destructive and non-read-only, and the description adds meaningful behavioral detail beyond that: it is a PUT, the payload is a top-level JSON array, existing entries should be preserved, and the operation 'may notify recipients or change tenant data.' It also clearly states the write opt-in and confirm requirement, which goes beyond the raw annotation flags.

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 front-loaded with purpose, endpoint, and the critical array caveat, which is good. However, the note about preserving PUT from DEFINITION despite a Python sample calling requests.post reads as implementation history rather than tool guidance, and the repeated instruction to 'consult the official operation' makes the text feel somewhat padded.

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 destructive mutation with four parameters, an open-world body schema, and no output schema, the description covers authorization, payload shape, and side effects reasonably well. But it leaves exact field semantics and replacement behavior to an external reference, and it never explains what a caller should expect in the response, so it is not fully self-contained.

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 schema's body property is a recursive anyOf with only a generic description, so the description adds real value by clarifying that the request body is a JSON array and that senderType, sender, and editScenarios describe array entries rather than root object keys. It does not fully define the allowed values or nested semantics, but it meaningfully compensates for the schema's lack of structure.

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 first sentence names a specific action and resource: 'Set scenario sender permissions', backed by an explicit endpoint PUT /api/xm/1/scenarios/{scenarioId}/sender-permissions. It is clear and specific, but it does not distinguish itself from related sibling tools such as xmatters_get_scenario_sender_permissions or xmatters_update_sender_permissions, so it stops short of a 5.

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 gives no guidance about when to use this tool versus alternatives like xmatters_update_sender_permissions or xmatters_get_scenario_sender_permissions. It provides invocation prerequisites such as write opt-in and confirm:true, but those are safety requirements, not usage routing, so an agent is left to infer the correct selection context.

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