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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds only the scoping behavior; it says nothing about reversibility, permission requirements, or how many articles are affected.

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?

A single front-loaded sentence with no filler; the scope constraint follows immediately after the action, which is exactly the right ordering.

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 no-required-param bulk mutation with annotations carrying the destructive/idempotent flags and no output schema, the description is close to sufficient. The only real gap is whether feed_id and folder_id are mutually exclusive or combinable.

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 both feed_id and folder_id are already documented in the schema. The description merely restates their combined effect ('limited to one feed or folder') without adding format, precedence, or mutual-exclusion guidance.

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 (mark articles as read) plus the scope option (all, or one feed/folder). It is clearly distinguishable from the sibling mark_as_read by the word 'all', though it never explicitly contrasts with that sibling.

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 through 'optionally limited to one feed or folder', telling the agent it can scope the bulk operation. It does not state when to prefer this over mark_as_read/mark_as_unread, nor what happens if both feed_id and folder_id are supplied.

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