channels_modify_permissions

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds useful context by clarifying that the tool replaces existing overwrites, explains the `type` encoding, and discloses the return shape `{updated, channel_id, overwrite_id}`. No contradiction with 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?

The description is well-structured with bold labels and bullet points, presenting the purpose, usage guidance, parameter notes, and return value in a compact format. No redundant sentences.

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?

Given the tool's moderate complexity, the description covers purpose, usage guidelines, parameter semantics, and returns. It also references the sibling delete tool for exclusions. With an output schema present, it does not need to detail return values further; the description is sufficient for an agent to select and invoke the tool.

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 input schema covers all 6 parameters with descriptions, so the baseline is 3. The description adds a concise explanation of `type` (0=role, 1=member) and that `allow`/`deny` are stringified bitfields, but this largely mirrors the schema descriptions. It provides minimal additional semantic value beyond the schema.

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 states 'Create or replace a permission overwrite for a role or user on a channel' with a specific verb and resource, and clearly distinguishes from `channels_delete_permissions`. It also specifies the scope (role or user) and the action (create/replace).

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?

It provides explicit 'When to use' examples like restricting a channel to a role or allowing moderators to manage messages, and 'When NOT to use' with a named alternative (`channels_delete_permissions`) for removing overwrites entirely.

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